Value of Right-Sided Cardiac Catheterization in Patients Undergoing Left-Sided Cardiac Catheterization for Evaluation of Coronary Artery Disease James A. Hill, MD, Ariel A. Miranda, MD, Stephen G. Keim, MD, Marshall H. Decker, MD, Jose I. Gonzalez, MD, and Charles R. Lambert, MD, PhD
The value of right-sided cardiac catheterization was assessed prospectively in 266 patients undergoing left-sided catheterization for evaluation of known or suspected coronary artery disease. Defore catheterization, data from right-sided catheterization was not felt to be necessary for clinical management. There were 6 f 2 extra minutes of procedure time and 66 f 63 extra seconds of fluoroscopy time used. Abnormalities were detected in 69 (36%) patients. These findings were unexpected in 37 of these patients and in 3 patients, further evaluation was prompted. However, management was altered in only 3 (1.5%) patients as a result of data obtained by right-sided catheterixation. In conclusion this additional procedure rarely adds clinically useful information about patients undergoing left-sided catheterization and angiography for coronary artery disease without a clinical indication for right-sided catheterixatttn. (Am J Cardiol1996;65:596-593)
I
n patients with signs and symptoms of valvular heart disease, heart failure, pulmonary hypertension and related problems, right-sided cardiac catheterization is indicated to obtain cardiac output, pressures and occasionally angiography and endomyocardial biopsy. Currently, however, most patients undergoing cardiac catheterization are being evaluated for chest pain and coronary artery disease and frequently undergo an assessment of left-sided function only. Many have questioned-3 the need for right-sided cardiac catheterization in this type of patient and current practice varies from one institution to another. In some laboratories both right- and left-sided catheterization are routinely performed and the patient is charged for both. In other laboratories, both are performed but the patient is charged only for left-sided catheterization and still in others, right-sided catheterization studies are not routinely performed. Retrospective studies suggest that right-sided catheterization in this situation, while not hazardous, does not provide information that alters patient management and therefore is probably not cost-effective or medically indicated. With the current emphasis on cost-consciousness and the increase in outpatient procedures, the question of whether routine right-sided catheterization should be done in a patient undergoing catheterization for evaluation of definite or possible coronary heart disease is important. This study was designed to evaluate prospectively the clinical importance and the cost of right-sided catheterization in patients undergoing leftsided catheterization for evaluation of possible or known coronary heart disease. METHODS Patient selection:
From the University of Florida College of Veterans Administration Medical Center, script received August 11, 1989; revised cepted October 30, 1989. Address for reprints: James A. Hill, University of Florida, Box J-277, JHMHC,
590
THE AMERICAN
JOURNAL
Medicine and the Gainesville Gainesville, Florida. Manumanuscript received and acMD, Division of Cardiology, Gainesville, Florida 32610.
OF CARDIOLOGY
VOLUME
65
Two-hundred patients undergoing evaluation for possible or definite coronary heart disease were selected prospectively from the population undergoing catheterization at the Shands Hospital at the University of Florida and the Gainesville Veterans Administration Medical Center. Selection was based on clinical evaluation by the cardiology staff that information from right-sided catheterization was not necessary. Patients were excluded if they had any of the following: clinically indicated right-sided catheterization for valvular heart disease; myocardial disease; suspected pulmonary hypertension; congestive heart failure; pericardial disease; congenital heart disease; cardiac transplanta-
tion; or acute myocardial infarction. Additionally, patients who had had a prior normal right-sided catheterization within 2 years without any intervening events were excluded. Catheterization procedure: Catheterization was performed via the femoral artery and vein. Local anesthesia was given to the appropriate site and venipuncture was performed. Using standard Seldinger technique, a sheath with a hemostatic diaphragm was placed for insertion of the catheters into the femoral vein. At that point, a 7Fr balloon flotation catheter with capabilities for measuring cardiac output by thermodilution was inserted and moved to the pulmonary artery using fluoroscopic and pressure monitoring. Cardiac output was then determined 3 times by the thermodilution technique. Fluoroscopy time was measured as the amount of fluoroscopy time taken to perform this procedure until the end of the cardiac output determination. The left-sided catheterization procedure was then carried out again via the femoral artery using a percutaneous technique. Arterial and mixed venous oxygen saturations were drawn and aortic and left ventricular pressures were recorded concomitantly with right-sided pressures by pullback. The balloon flotation catheter was then left in the inferior vena cava while the remainder of the procedure, including angiography, was performed. Because some have used change in right-sided hemodynamics after contrast as an indicator of poor cardiac reserve, nonionic or low osmolar contrast agents were used in all patients to minimize hemodynamic changes due to contrast agent administration. Date recorded: HEMODYNAMIC MEASUREMENTS: Normal values for variables are as follows: right atrium pressure 18 mm Hg; right ventricle systolic pressure 130 mm Hg; right ventricle end-diastolic pressure 58 mm Hg; pulmonary artery systolic pressure 530 mm Hg; pulmonary artery diastolic pressure 5 12 mm Hg; pulmonary capillary wedge pressure 5 12 mm Hg; and cardiac index 22.25 liters/min/m*. OXYGEN SATURATION: The normal difference between saturation from the pulmonary artery and saturation from the aorta was considered to be 20 to 30%. PROCEDURE TIMES: The time for the equipment setup for the right-sided catheterization was not recorded on an individual basis, but was a calculated average. Procedure time was measured as time from initial venous access until the end of cardiac output determination. Duration of fluoroscopy was determined for performing the right-sided catheterization only. COMPLICATIONS: Complications including arrhythmias necessitating treatment, cardiac perforation, deepvein thrombosis or bleeding related to the performance of right-sided catheterization alone were considered complications for the purpose of this study. Complications relating to the arterial procedure were not reported. After the procedure was completed, the staff cardiologist performing the catheterization addressed the following 3 questions: did the data from the right-sided catheterization alter the performance of the procedure? (e.g., pulmonary angiography, detailed oximetry mea-
TABLE I Clinical Characteristics
and Catheterization
Age (YES)
60f 11 150/50
Sex: M/F CAD SIgnkant (>50% stenosis) None or ~50% stenosis Hemodynamlcs*+ Rtght atnum Right ventricle Systolic End-dlastok Pulmonary artery diastok Pulmonary capillary wedge Cardiac Index (Ilters/mln/m2) AVDOE (% saturation) Procedure time (mtn) Fluoroscopy time (s) *All data are mean f standard AVDO, = arterlovenous my,+?”
devlatlon. Content
Data
149
51 5f3 26 f 8 6f3
llf5 9f5 351 25f 5 6f2 86 f 63 iall pressures measured dfference; CAD = coronary
,n m m tig artery d,sease
surements, etc.); were any unsuspected abnormalities detected as a result of the right-sided catheterization?; and did data from the right-sided catheterization alter patient management? Cost determination: In the Southeast section of the country, a formal survey of 4 academic center laboratories and an informal survey of 7 laboratories, including academic and community hospitals, was undertaken. The laboratory directors were asked what the added technical and professional costs were when a right-sided heart catheterization was performed in addition to a standard left-sided heart catheterization, including coronary and left ventricular angiography. A mean value was determined and used to calculate the final cost. RESULTS Demographic and mean data from the 200 patients studied are listed in Table I. These patients seemed to comprise a fairly representative group undergoing cardiac catheterization and coronary angiography. Procedure time: Additional time was necessary for the technologists to set up the procedure. All supplies were disposable and the equipment for right-sided heart catheterization in our laboratories is prepackaged as a set for this purpose. The calculated time for additional laboratory setup was 5 minutes. Calibration for the cardiac output computer and hemodynamic measurements was incorporated into the procedure time. The procedure time as calculated from venous accessto the end of the cardiac output determination was 6 f 2 min (range 2 to 14). In addition, 86 f 63 seconds (range 6 to 324) of extra fluoroscopy time was used for the right-sided catheterization. Compliitiens: Complications related to right-sided catheterization were limited to 1 episode of transient right bundle branch block in a patient with a previously normal electrocardiogram and normal coronary arteries. This resolved within 1 hour of the procedure without sequelae. No patient required a temporary pacemaker during the catheterization or angiography. Abnormalities detected, alteration of catheterization and management changes: There were 69 (35%)
patients who had at least 1 and often >l value outside THE AMERICAN
JOURNAL
OF CARDIOLOGY
MARCH
1. 1990
591
the normal range for right-sided hemodynamics. This group included 22 patients with an elevated right atria1 pressure (range 9 to 17 mm Hg), 39 with an elevated right ventricular systolic pressure (range 31 to 70 mm Hg), 29 with an elevated right ventricular end-diastolic pressure (range 9 to 20 mm Hg), 52 with an elevated pulmonary artery diastolic pressure (range 13 to 32 mm Hg) and 40 with an elevated pulmonary capillary wedge pressure (range 13 to 38 mm Hg). In addition, 53 patients had a reduced cardiac index (range 1.3 to 2.23 liters/min/m*), 20 had a widened arteriovenous oxygen difference and 20 had a narrowed arteriovenous oxygen difference. No patient was noted to have a pulmonic valve gradient. The catheterization procedure was altered in only 2 patients as a result of data obtained from the right-sided catheterization. One patient had high right-sided pressures from a presumed right ventricular infarction and more cautious fluid administration was used with no complications. In 1 other patient, a narrow arteriovenous oxygen difference prompted more complete oxygen saturation measurements, which failed to reveal a shunt. Unexpected findings were noted in 37 patients. These findings were generally mild right-sided pressure abnormalities and resulted in no further evaluation in 33 patients. In 4 patients, further diagnostic tests were performed as a result of unexplained findings from right-sided catheterization. These included 3 patients who had 2-dimensional echocardiograms and 1 patient who had studies performed to rule out sleep apnea as a cause of moderate pulmonary hypertension. Despite all these abnormalities, however, data from right-sided catheterization altered management in only 3 (1.5%) patients. One patient had pulmonary hypertension out of proportion to the degree of left ventricular dysfunction and treatment was more aggressively instituted with afterload reduction and pulmonary vasodilators. Another patient had unsuspected severe pulmonary hypertension with normal coronary arteries and left ventricular function and was more aggressively treated for this. The final patient had mitral stenosis discovered when simultaneous left ventricular and pulmonary cap illary wedge pressures were measured. This patient had been seen and examined by 3 staff cardiologists, all of whom missed the mitral stenosis which was later confirmed by 2-dimensional echocardiography; the patient received mitral valve replacement in addition to coronary artery bypass surgery. Cost: Using the mean values determined from our survey, each right-sided catheterization study cost $775 or a total of $155,000 for the study group. With the yield of 3 patients in this study who had information discovered that influenced management, obtaining this information cost $51,667 per patient. DISCUSSION
This is the first prospective study of its type to test the value of right-sided catheterization in patients undergoing left-sided catheterization for evaluation of known or suspected coronary artery disease. Most previ592
THE AMERICAN
JOURNAL
OF CARDIOLOGY
VOLUME
65
ous reports have been retrospective and thus, subject to patient selection bias. In the current study, all patients were evaluated before catheterization by a staff cardiologist and a cardiology trainee who determined that data obtained from right-sided catheterization was not essential to management. A recent retrospective study reported by Barron et al4 suggested that abnormal findings discovered by right-sided catheterization might potentially influence patient management, but it is not possible to determine if management was actually altered. In a similar retrospective analysis, Shanes et al5 found insufficient abnormalities to justify the routine use of right-sided catheterization in 219 patients evaluated. Another study reported by Friedman6 evaluated 100 consecutive male patients undergoing catheterization for coronary artery disease. He found that both prognostic information and data important to the management of the patients were obtained primarily from the left-sided catheterization. Therefore, he concluded that the routine use of the right-sided catheterization was unnecessary in this type of patient. There are 2 major issues when considering whether to perform right-sided catheterization in patients with known or suspected coronary artery disease. These issues are how right-sided catheterization data will influence medical therapy and how it will guide perioperative management if coronary surgery is performed. Changes in medical management are primarily related to the patient’s symptomatic status, demonstrable ischemia on some sort of stress testing or measures aimed at improving left ventricular function. All of these aspects are either understood before catheterization, are assessed afterward by appropriate noninvasive studies or are assessed by left ventriculography. Regarding perioperative management in patients undergoing straightforward coronary artery bypass surgery, most information pertinent to appropriate anesthetic management can be concluded from measurement of the left ventricular end-diastolic pressure. Moreover, surgical risk assessment is well correlated with ejection fraction. Except in unusual circumstances, it therefore appears that data obtained from right-sided catheterization in such patients is not necessary for appropriate perioperative management. Another consideration is whether important information is missed regarding conditions that affect the heart, other than coronary artery disease, by not performing right-sided catheterization routinely. Our data suggest that there is occasional information obtained that influences patient management but only in a very small percentage. However, it is important to emphasize that if catheterization procedures are not individualized as they were in this study, the potential for missing important clinical information is probably greater. Cardiac catheterization and angiography must remain as only part of a thorough clinical evaluation. The final consideration is cost. Attempts to calculate costs in different laboratories resulted in the discovery of numerous confusing factors. Costs for the laboratory fee ranged from $0 to $1,800 (mean 490). An addition-
al professional fee ranged from $60 to $729 (mean 285). The difficulty in arriving at a typical charge was related to the fact that each laboratory used a slightly different method for patient charges. The variability of these methods included the following: itemizing supplies that were used; itemizing costs by other hospital areas such as a central sterile supply area; itemizing costs per actual procedure performed such as cardiac output, hemodynamic measurement, etc; charging an inclusive fee for right-sided catheterization; and charging an inclusive fee for the entire study regardless of what was performed. While mention of cost has been made in other reported studies, none have evaluated all aspects of it in a systematic way. Because of the nature of different billing practices and allowances for payment, it is not clear what method of cost determination is accurate. However, the cost of this procedure is not inconsequential. Even if professional fees are not included, there are still issues of equipment and technical and professional time, which can be significant in a high volume laboratory. Finally, the amount of radiation exposure is increased to both the patient and staff. This study has shown that, in patients undergoing left-sided catheterization for evaluation of chest
pain, the yield of important diagnostic information from right-sided catheterization is low and the cost is high. It is necessary to stress, however, that this does not preclude the use of or eliminate the need for right-sided catheterization. When there is a diagnostic question not clearly answered by left-sided catheterization alone or if the clinical circumstances suggest conditions other than simple coronary artery disease with relatively normal left ventricular function, right-sided catheterization is very appropriate and indicated. REFERENCES 1. Greene DC. during coronary
diouasc
Diagn
2. Samet
Right heart arteriography
catheterization for suspected
and temporary coronary artery
pacemaker insertion disease. Carher Car-
1984;10.-429-430.
P. The
complete
cardiac
catheterization.
Cather
Cardiouasc
Diagn
1984:10:431-432. 3. Levin DC. Right heart catheterization in the evaluation of patients with suspected coronary artery disease. Cathe? Cardiouasc Diagn 1985;11:217. 4. Barron JT, Ruggie N, Uretz E, Messer JV. Findings on routine right heart catheterization in patients with suspected coronary artery disease. Am Heart J
1988;115;1193-1198. 5. Shanes JG, Stein heart catheterization
MA, Dierenfeldt BJ, Kondos GT. The value of routine right in patients undergoing coronary arteriography. Am Heart J
1987;113:1261-1263. 6. Friedman
HS. Right-heart
catheterization
in coronary
artery
disease.
Angiob-
gy 1978;12:878-887.
THE
AMERICAN
JOURNAL
OF CARDIOLOGY
MARCH
1, 1990
593
The value of right-sided cardiac catheterization was assessed prospectively in 266 patients undergoing left-sided catheterization for evaluation of known or suspected coronary artery disease. Defore catheterization, data from right-sided catheterization was not felt to be necessary for clinical management. There were 6 f 2 extra minutes of procedure time and 66 f 63 extra seconds of fluoroscopy time used. Abnormalities were detected in 69 (36%) patients. These findings were unexpected in 37 of these patients and in 3 patients, further evaluation was prompted. However, management was altered in only 3 (1.5%) patients as a result of data obtained by right-sided catheterixation. In conclusion this additional procedure rarely adds clinically useful information about patients undergoing left-sided catheterization and angiography for coronary artery disease without a clinical indication for right-sided catheterixatttn. (Am J Cardiol1996;65:596-593)
I
n patients with signs and symptoms of valvular heart disease, heart failure, pulmonary hypertension and related problems, right-sided cardiac catheterization is indicated to obtain cardiac output, pressures and occasionally angiography and endomyocardial biopsy. Currently, however, most patients undergoing cardiac catheterization are being evaluated for chest pain and coronary artery disease and frequently undergo an assessment of left-sided function only. Many have questioned-3 the need for right-sided cardiac catheterization in this type of patient and current practice varies from one institution to another. In some laboratories both right- and left-sided catheterization are routinely performed and the patient is charged for both. In other laboratories, both are performed but the patient is charged only for left-sided catheterization and still in others, right-sided catheterization studies are not routinely performed. Retrospective studies suggest that right-sided catheterization in this situation, while not hazardous, does not provide information that alters patient management and therefore is probably not cost-effective or medically indicated. With the current emphasis on cost-consciousness and the increase in outpatient procedures, the question of whether routine right-sided catheterization should be done in a patient undergoing catheterization for evaluation of definite or possible coronary heart disease is important. This study was designed to evaluate prospectively the clinical importance and the cost of right-sided catheterization in patients undergoing leftsided catheterization for evaluation of possible or known coronary heart disease. METHODS Patient selection:
From the University of Florida College of Veterans Administration Medical Center, script received August 11, 1989; revised cepted October 30, 1989. Address for reprints: James A. Hill, University of Florida, Box J-277, JHMHC,
590
THE AMERICAN
JOURNAL
Medicine and the Gainesville Gainesville, Florida. Manumanuscript received and acMD, Division of Cardiology, Gainesville, Florida 32610.
OF CARDIOLOGY
VOLUME
65
Two-hundred patients undergoing evaluation for possible or definite coronary heart disease were selected prospectively from the population undergoing catheterization at the Shands Hospital at the University of Florida and the Gainesville Veterans Administration Medical Center. Selection was based on clinical evaluation by the cardiology staff that information from right-sided catheterization was not necessary. Patients were excluded if they had any of the following: clinically indicated right-sided catheterization for valvular heart disease; myocardial disease; suspected pulmonary hypertension; congestive heart failure; pericardial disease; congenital heart disease; cardiac transplanta-
tion; or acute myocardial infarction. Additionally, patients who had had a prior normal right-sided catheterization within 2 years without any intervening events were excluded. Catheterization procedure: Catheterization was performed via the femoral artery and vein. Local anesthesia was given to the appropriate site and venipuncture was performed. Using standard Seldinger technique, a sheath with a hemostatic diaphragm was placed for insertion of the catheters into the femoral vein. At that point, a 7Fr balloon flotation catheter with capabilities for measuring cardiac output by thermodilution was inserted and moved to the pulmonary artery using fluoroscopic and pressure monitoring. Cardiac output was then determined 3 times by the thermodilution technique. Fluoroscopy time was measured as the amount of fluoroscopy time taken to perform this procedure until the end of the cardiac output determination. The left-sided catheterization procedure was then carried out again via the femoral artery using a percutaneous technique. Arterial and mixed venous oxygen saturations were drawn and aortic and left ventricular pressures were recorded concomitantly with right-sided pressures by pullback. The balloon flotation catheter was then left in the inferior vena cava while the remainder of the procedure, including angiography, was performed. Because some have used change in right-sided hemodynamics after contrast as an indicator of poor cardiac reserve, nonionic or low osmolar contrast agents were used in all patients to minimize hemodynamic changes due to contrast agent administration. Date recorded: HEMODYNAMIC MEASUREMENTS: Normal values for variables are as follows: right atrium pressure 18 mm Hg; right ventricle systolic pressure 130 mm Hg; right ventricle end-diastolic pressure 58 mm Hg; pulmonary artery systolic pressure 530 mm Hg; pulmonary artery diastolic pressure 5 12 mm Hg; pulmonary capillary wedge pressure 5 12 mm Hg; and cardiac index 22.25 liters/min/m*. OXYGEN SATURATION: The normal difference between saturation from the pulmonary artery and saturation from the aorta was considered to be 20 to 30%. PROCEDURE TIMES: The time for the equipment setup for the right-sided catheterization was not recorded on an individual basis, but was a calculated average. Procedure time was measured as time from initial venous access until the end of cardiac output determination. Duration of fluoroscopy was determined for performing the right-sided catheterization only. COMPLICATIONS: Complications including arrhythmias necessitating treatment, cardiac perforation, deepvein thrombosis or bleeding related to the performance of right-sided catheterization alone were considered complications for the purpose of this study. Complications relating to the arterial procedure were not reported. After the procedure was completed, the staff cardiologist performing the catheterization addressed the following 3 questions: did the data from the right-sided catheterization alter the performance of the procedure? (e.g., pulmonary angiography, detailed oximetry mea-
TABLE I Clinical Characteristics
and Catheterization
Age (YES)
60f 11 150/50
Sex: M/F CAD SIgnkant (>50% stenosis) None or ~50% stenosis Hemodynamlcs*+ Rtght atnum Right ventricle Systolic End-dlastok Pulmonary artery diastok Pulmonary capillary wedge Cardiac Index (Ilters/mln/m2) AVDOE (% saturation) Procedure time (mtn) Fluoroscopy time (s) *All data are mean f standard AVDO, = arterlovenous my,+?”
devlatlon. Content
Data
149
51 5f3 26 f 8 6f3
llf5 9f5 351 25f 5 6f2 86 f 63 iall pressures measured dfference; CAD = coronary
,n m m tig artery d,sease
surements, etc.); were any unsuspected abnormalities detected as a result of the right-sided catheterization?; and did data from the right-sided catheterization alter patient management? Cost determination: In the Southeast section of the country, a formal survey of 4 academic center laboratories and an informal survey of 7 laboratories, including academic and community hospitals, was undertaken. The laboratory directors were asked what the added technical and professional costs were when a right-sided heart catheterization was performed in addition to a standard left-sided heart catheterization, including coronary and left ventricular angiography. A mean value was determined and used to calculate the final cost. RESULTS Demographic and mean data from the 200 patients studied are listed in Table I. These patients seemed to comprise a fairly representative group undergoing cardiac catheterization and coronary angiography. Procedure time: Additional time was necessary for the technologists to set up the procedure. All supplies were disposable and the equipment for right-sided heart catheterization in our laboratories is prepackaged as a set for this purpose. The calculated time for additional laboratory setup was 5 minutes. Calibration for the cardiac output computer and hemodynamic measurements was incorporated into the procedure time. The procedure time as calculated from venous accessto the end of the cardiac output determination was 6 f 2 min (range 2 to 14). In addition, 86 f 63 seconds (range 6 to 324) of extra fluoroscopy time was used for the right-sided catheterization. Compliitiens: Complications related to right-sided catheterization were limited to 1 episode of transient right bundle branch block in a patient with a previously normal electrocardiogram and normal coronary arteries. This resolved within 1 hour of the procedure without sequelae. No patient required a temporary pacemaker during the catheterization or angiography. Abnormalities detected, alteration of catheterization and management changes: There were 69 (35%)
patients who had at least 1 and often >l value outside THE AMERICAN
JOURNAL
OF CARDIOLOGY
MARCH
1. 1990
591
the normal range for right-sided hemodynamics. This group included 22 patients with an elevated right atria1 pressure (range 9 to 17 mm Hg), 39 with an elevated right ventricular systolic pressure (range 31 to 70 mm Hg), 29 with an elevated right ventricular end-diastolic pressure (range 9 to 20 mm Hg), 52 with an elevated pulmonary artery diastolic pressure (range 13 to 32 mm Hg) and 40 with an elevated pulmonary capillary wedge pressure (range 13 to 38 mm Hg). In addition, 53 patients had a reduced cardiac index (range 1.3 to 2.23 liters/min/m*), 20 had a widened arteriovenous oxygen difference and 20 had a narrowed arteriovenous oxygen difference. No patient was noted to have a pulmonic valve gradient. The catheterization procedure was altered in only 2 patients as a result of data obtained from the right-sided catheterization. One patient had high right-sided pressures from a presumed right ventricular infarction and more cautious fluid administration was used with no complications. In 1 other patient, a narrow arteriovenous oxygen difference prompted more complete oxygen saturation measurements, which failed to reveal a shunt. Unexpected findings were noted in 37 patients. These findings were generally mild right-sided pressure abnormalities and resulted in no further evaluation in 33 patients. In 4 patients, further diagnostic tests were performed as a result of unexplained findings from right-sided catheterization. These included 3 patients who had 2-dimensional echocardiograms and 1 patient who had studies performed to rule out sleep apnea as a cause of moderate pulmonary hypertension. Despite all these abnormalities, however, data from right-sided catheterization altered management in only 3 (1.5%) patients. One patient had pulmonary hypertension out of proportion to the degree of left ventricular dysfunction and treatment was more aggressively instituted with afterload reduction and pulmonary vasodilators. Another patient had unsuspected severe pulmonary hypertension with normal coronary arteries and left ventricular function and was more aggressively treated for this. The final patient had mitral stenosis discovered when simultaneous left ventricular and pulmonary cap illary wedge pressures were measured. This patient had been seen and examined by 3 staff cardiologists, all of whom missed the mitral stenosis which was later confirmed by 2-dimensional echocardiography; the patient received mitral valve replacement in addition to coronary artery bypass surgery. Cost: Using the mean values determined from our survey, each right-sided catheterization study cost $775 or a total of $155,000 for the study group. With the yield of 3 patients in this study who had information discovered that influenced management, obtaining this information cost $51,667 per patient. DISCUSSION
This is the first prospective study of its type to test the value of right-sided catheterization in patients undergoing left-sided catheterization for evaluation of known or suspected coronary artery disease. Most previ592
THE AMERICAN
JOURNAL
OF CARDIOLOGY
VOLUME
65
ous reports have been retrospective and thus, subject to patient selection bias. In the current study, all patients were evaluated before catheterization by a staff cardiologist and a cardiology trainee who determined that data obtained from right-sided catheterization was not essential to management. A recent retrospective study reported by Barron et al4 suggested that abnormal findings discovered by right-sided catheterization might potentially influence patient management, but it is not possible to determine if management was actually altered. In a similar retrospective analysis, Shanes et al5 found insufficient abnormalities to justify the routine use of right-sided catheterization in 219 patients evaluated. Another study reported by Friedman6 evaluated 100 consecutive male patients undergoing catheterization for coronary artery disease. He found that both prognostic information and data important to the management of the patients were obtained primarily from the left-sided catheterization. Therefore, he concluded that the routine use of the right-sided catheterization was unnecessary in this type of patient. There are 2 major issues when considering whether to perform right-sided catheterization in patients with known or suspected coronary artery disease. These issues are how right-sided catheterization data will influence medical therapy and how it will guide perioperative management if coronary surgery is performed. Changes in medical management are primarily related to the patient’s symptomatic status, demonstrable ischemia on some sort of stress testing or measures aimed at improving left ventricular function. All of these aspects are either understood before catheterization, are assessed afterward by appropriate noninvasive studies or are assessed by left ventriculography. Regarding perioperative management in patients undergoing straightforward coronary artery bypass surgery, most information pertinent to appropriate anesthetic management can be concluded from measurement of the left ventricular end-diastolic pressure. Moreover, surgical risk assessment is well correlated with ejection fraction. Except in unusual circumstances, it therefore appears that data obtained from right-sided catheterization in such patients is not necessary for appropriate perioperative management. Another consideration is whether important information is missed regarding conditions that affect the heart, other than coronary artery disease, by not performing right-sided catheterization routinely. Our data suggest that there is occasional information obtained that influences patient management but only in a very small percentage. However, it is important to emphasize that if catheterization procedures are not individualized as they were in this study, the potential for missing important clinical information is probably greater. Cardiac catheterization and angiography must remain as only part of a thorough clinical evaluation. The final consideration is cost. Attempts to calculate costs in different laboratories resulted in the discovery of numerous confusing factors. Costs for the laboratory fee ranged from $0 to $1,800 (mean 490). An addition-
al professional fee ranged from $60 to $729 (mean 285). The difficulty in arriving at a typical charge was related to the fact that each laboratory used a slightly different method for patient charges. The variability of these methods included the following: itemizing supplies that were used; itemizing costs by other hospital areas such as a central sterile supply area; itemizing costs per actual procedure performed such as cardiac output, hemodynamic measurement, etc; charging an inclusive fee for right-sided catheterization; and charging an inclusive fee for the entire study regardless of what was performed. While mention of cost has been made in other reported studies, none have evaluated all aspects of it in a systematic way. Because of the nature of different billing practices and allowances for payment, it is not clear what method of cost determination is accurate. However, the cost of this procedure is not inconsequential. Even if professional fees are not included, there are still issues of equipment and technical and professional time, which can be significant in a high volume laboratory. Finally, the amount of radiation exposure is increased to both the patient and staff. This study has shown that, in patients undergoing left-sided catheterization for evaluation of chest
pain, the yield of important diagnostic information from right-sided catheterization is low and the cost is high. It is necessary to stress, however, that this does not preclude the use of or eliminate the need for right-sided catheterization. When there is a diagnostic question not clearly answered by left-sided catheterization alone or if the clinical circumstances suggest conditions other than simple coronary artery disease with relatively normal left ventricular function, right-sided catheterization is very appropriate and indicated. REFERENCES 1. Greene DC. during coronary
diouasc
Diagn
2. Samet
Right heart arteriography
catheterization for suspected
and temporary coronary artery
pacemaker insertion disease. Carher Car-
1984;10.-429-430.
P. The
complete
cardiac
catheterization.
Cather
Cardiouasc
Diagn
1984:10:431-432. 3. Levin DC. Right heart catheterization in the evaluation of patients with suspected coronary artery disease. Cathe? Cardiouasc Diagn 1985;11:217. 4. Barron JT, Ruggie N, Uretz E, Messer JV. Findings on routine right heart catheterization in patients with suspected coronary artery disease. Am Heart J
1988;115;1193-1198. 5. Shanes JG, Stein heart catheterization
MA, Dierenfeldt BJ, Kondos GT. The value of routine right in patients undergoing coronary arteriography. Am Heart J
1987;113:1261-1263. 6. Friedman
HS. Right-heart
catheterization
in coronary
artery
disease.
Angiob-
gy 1978;12:878-887.
THE
AMERICAN
JOURNAL
OF CARDIOLOGY
MARCH
1, 1990
593
