© 2015, Wiley Periodicals, Inc. DOI: 10.1111/echo.12912
Echocardiography
ORIGINAL INVESTIGATION
Impact of Severe Tricuspid Regurgitation on Accuracy of Echocardiographic Pulmonary Artery Systolic Pressure Estimation € € Ebru Ozpelit, M.D.,* Bahri Akdeniz, M.D.,* Emre Mehmet Ozpelit, M.D.,† Sedat Tas, M.D.,* Erkan Alpaslan, € M.D.,* Selen Bozkurt, Ph.D.,‡ Abdulla Arslan, M.D.,* and Ozer Badak, M.D.* *Department of Cardiology, School of Medicine, Dokuz Eylul University, Izmir, Turkey; †Department of Cardiology, School of Medicine, Izmir University, Medicalpark Hospital, Izmir, Turkey; and ‡Department of Biostatistics and Medical Informatics, School of Medicine, Akdeniz University, Antalya, Turkey
Introduction: Transthoracic Doppler echocardiography (DE) is recommended for screening and monitorization of pulmonary arterial hypertension (PAH). However, some recent studies have suggested that Doppler echocardiographic pulmonary artery systolic pressure (PASP) estimates may frequently be inaccurate. Some hemodynamic and echocardiographic factors are known to contribute to discordant results. The aim of this study was to determine whether severe tricuspid regurgitation (TR) has any impact on true estimation of PASP by DE. Materials and Methods: We retrospectively identified all PAH patients who underwent right heart catheterization (RHC) and had an echocardiogram within the same hospitalization period. Patients were divided into two groups according to the presence of severe TR: Group 1 consisted of 36 patients with mild–moderate TR and group 2 of 36 patients with severe TR. For these two groups, the agreement between echocardiographic and catheterization PASP measurements was evaluated by Bland–Altman analysis, separately. Results: In group 1, the bias for the echocardiographic estimates of the PASP was 2.5 mmHg and 62.5% of the echocardiographic estimates were accurate (≤10 mmHg difference with RHC measurement). In group 2, the bias was 16.25 mmHg and echocardiography was accurate in 37.5% of the patients. To clarify the association between PASP overestimation on DE and the presence of severe TR, regression analysis was performed. Severe TR was found as the only independent predictor of PASP overestimation on echocardiography after multivariate analysis. Conclusion: The results of the study show that in patients with PAH, the presence of severe TR is associated with an overestimated PASP measurement on echocardiography. (Echocardiography 2015;00:1–8) Key words: Doppler echocardiography, pulmonary artery pressure, tricuspid regurgitation, cardiac hemodynamics, cardiac catheterization, pulmonary hypertension Pulmonary arterial hypertension (PAH) is a progressive disease of the pulmonary vasculature that leads to increased pulmonary vascular resistance (PVR), right heart failure, and death. Currently, PAH is diagnosed by right heart catheterization (RHC); the main disadvantage of RHC is that it is an invasive procedure and is associated with some morbidity (1.1%) and mortality (0.055%) even when performed at experienced centers.1 Thus, noninvasive alternatives are often used to monitor disease progression and response to therapy. Based on reports of a high correlation with invasive The authors received no financial support for the research, authorship, and/or publication of this article. Address for correspondence and reprint requests: Dr. Ebru Ozpelit, M.D., Department of Cardiology, Dokuz Eylul University Hospital, Inciraltı-Izmir, PK:35340 Turkey. Fax: +902322792565; E-mail: [email protected]
measurements, Doppler echocardiography (DE) is recommended as a tool for early screening and assessment of patients suspected of having PAH. Using the modified Bernoulli equation, an estimate of right atrial pressure (RAP) is added to the peak tricuspid regurgitant (TR) jet to approximate right ventricular systolic pressure (RVSP), which is equal to pulmonary arterial systolic pressure (PASP) in the absence of a pulmonary valve gradient.2 In spite of its widespread use, the accuracy and reproducibility of DE in estimating PASP have recently been questioned.3,4 The most common reason for discordant DE and RHC PASP results is inadequate TR jet signal. Some hemodynamic factors such as pulmonary capillary wedge (PCWP) were also proposed as a contributing factor for discordant results. However, until now, no study exists investigating the role of severe TR on agreement between Doppler 1
€ Ozpelit, et al.
and RHC PASP measurements. Severe TR is a common finding in patients with PAH, and it occurs secondarily to elevated pulmonary vascular resistance (PVR) and/or right ventricular (RV) dilatation. It is known that severe TR highly alters the hemodynamic interaction of right heart structures. In this study, we aimed to investigate whether severe TR has any impact on echocardiographic estimation of PASP. We hypothesized that the altered hemodynamic interaction of right heart structures in severe TR may severely contribute to the true estimation of PASP and RAP as well. Materials and Methods: Study Population: All consecutive RHCs, performed in pulmonary hypertension unit of DEU Hospital from January 1, 2010 to July 2013, were reviewed. Patients with mean PAP >25 mmHg at RHC and who underwent echocardiographic examination within the same hospitalization period were eligible for inclusion in this study. Exclusion criteria of the study were as follows: the presence of an insufficient quality of echo imaging, long-time interval between RHC and echo examination (>3 days), organic pathology of tricuspid valve on echocardiography including significant coaptation defect, minimal or no tricuspid regurgitant jet on echocardiography, left ventricular systolic dysfunction, more than moderate mitral and aortic valve disease, and uncorrected left-to-right shunts. Patients did not receive any specific PAH therapy, and no modification of actual diuretic therapy was made between TTE and RHC. Patients’ demographical, laboratory and clinical parameters, including BNP values, 6-minute walking distance (6MWD), etiology of pulmonary hypertension and functional class (FC), were recorded. Right Heart Catheterization: Right heart catheterization was performed at rest, without sedation, by an experienced cardiologist (BA). Measurements of PAP, RAP, and PCWP were taken at end-expiration. Cardiac output (Q) was measured by indirect Fick method with an assumed O2 consumption of the patient. Cardiac index (CI) was calculated as Q divided by body surface area. Pulmonary vascular resistance was calculated as mPAP minus left atrial pressure divided by Q. Transpulmonary gradient was calculated as the difference between mPAP and PCWP. Transthoracic Doppler Echocardiography: All patients had a comprehensive two-dimensional DE protocol within the same hospitalization
2
period with RHC, as described previously. Echocardiograms were performed by two experienced € using a Philips HD 11 cardiologists (BA and EO) XE machine with a 3.2-MHz transducer (Philips, Andover, MA, USA). Standard two-dimensional echocardiographic measurements were carried out according to recommendations of the American Society of Echocardiography.5 The left atrial (LA) and right atrial (RA) areas were traced manually and measured at end-systole from the twodimensional apical four-chamber view. RV internal end-diastolic diameter (apical four-chamber view), RV wall thickness (subcostal view), and right ventricular fractional area change (RFAC) were also obtained during 2D examination. Right ventricular fractional area change (RFAC) was calculated as RV end-diastolic area (RVEDA) minus RV end-systolic area (RVESA) divided by RVEDA in which measurements were obtained from apical four-chamber view.6 At apical four-chamber view, M-mode recording of the long axis was taken from the lateral side of the tricuspid annulus. The maximal distance of endocardial motion during systolic phase was defined as TAPSE.6 Mitral and tricuspid flow (TF) velocities were obtained with the sample volume placed at the tip of the mitral and tricuspid valve leaflets, respectively. The presence of valvular regurgitation was determined by color Doppler echocardiography. Tricuspid regurgitation was mostly quantified by jet area as follows: mild TR = jet area 10 cm2. Vena contracta and effective regurgitant orifice area were also measured when available.7 Pulmonary artery flow velocity was recorded from the parasternal shortaxis view with the sample volume placed at the central position. Tricuspid regurgitation velocity signal was recorded in multiple views (tricuspid inflow, parasternal short-axis, and apical fourchamber) with continuous wave spectral Doppler. Using the highest obtainable maximum velocity from these Doppler profiles, peak TR gradient was determined using the modified Bernoulli equation [4 9 (tricuspid regurgitation velocity)2]. The inferior vena cava (IVC) was imaged from the subcostal view while patients were asked to rapidly inhale or “sniff” during imaging. Estimated RAP was determined from the IVC size and the inspiratory degree of IVC collapse as follows: IVC >2.5 cm with no inspiratory collapse = 20 mmHg, IVC size >2.5 cm with
Echocardiography
ORIGINAL INVESTIGATION
Impact of Severe Tricuspid Regurgitation on Accuracy of Echocardiographic Pulmonary Artery Systolic Pressure Estimation € € Ebru Ozpelit, M.D.,* Bahri Akdeniz, M.D.,* Emre Mehmet Ozpelit, M.D.,† Sedat Tas, M.D.,* Erkan Alpaslan, € M.D.,* Selen Bozkurt, Ph.D.,‡ Abdulla Arslan, M.D.,* and Ozer Badak, M.D.* *Department of Cardiology, School of Medicine, Dokuz Eylul University, Izmir, Turkey; †Department of Cardiology, School of Medicine, Izmir University, Medicalpark Hospital, Izmir, Turkey; and ‡Department of Biostatistics and Medical Informatics, School of Medicine, Akdeniz University, Antalya, Turkey
Introduction: Transthoracic Doppler echocardiography (DE) is recommended for screening and monitorization of pulmonary arterial hypertension (PAH). However, some recent studies have suggested that Doppler echocardiographic pulmonary artery systolic pressure (PASP) estimates may frequently be inaccurate. Some hemodynamic and echocardiographic factors are known to contribute to discordant results. The aim of this study was to determine whether severe tricuspid regurgitation (TR) has any impact on true estimation of PASP by DE. Materials and Methods: We retrospectively identified all PAH patients who underwent right heart catheterization (RHC) and had an echocardiogram within the same hospitalization period. Patients were divided into two groups according to the presence of severe TR: Group 1 consisted of 36 patients with mild–moderate TR and group 2 of 36 patients with severe TR. For these two groups, the agreement between echocardiographic and catheterization PASP measurements was evaluated by Bland–Altman analysis, separately. Results: In group 1, the bias for the echocardiographic estimates of the PASP was 2.5 mmHg and 62.5% of the echocardiographic estimates were accurate (≤10 mmHg difference with RHC measurement). In group 2, the bias was 16.25 mmHg and echocardiography was accurate in 37.5% of the patients. To clarify the association between PASP overestimation on DE and the presence of severe TR, regression analysis was performed. Severe TR was found as the only independent predictor of PASP overestimation on echocardiography after multivariate analysis. Conclusion: The results of the study show that in patients with PAH, the presence of severe TR is associated with an overestimated PASP measurement on echocardiography. (Echocardiography 2015;00:1–8) Key words: Doppler echocardiography, pulmonary artery pressure, tricuspid regurgitation, cardiac hemodynamics, cardiac catheterization, pulmonary hypertension Pulmonary arterial hypertension (PAH) is a progressive disease of the pulmonary vasculature that leads to increased pulmonary vascular resistance (PVR), right heart failure, and death. Currently, PAH is diagnosed by right heart catheterization (RHC); the main disadvantage of RHC is that it is an invasive procedure and is associated with some morbidity (1.1%) and mortality (0.055%) even when performed at experienced centers.1 Thus, noninvasive alternatives are often used to monitor disease progression and response to therapy. Based on reports of a high correlation with invasive The authors received no financial support for the research, authorship, and/or publication of this article. Address for correspondence and reprint requests: Dr. Ebru Ozpelit, M.D., Department of Cardiology, Dokuz Eylul University Hospital, Inciraltı-Izmir, PK:35340 Turkey. Fax: +902322792565; E-mail: [email protected]
measurements, Doppler echocardiography (DE) is recommended as a tool for early screening and assessment of patients suspected of having PAH. Using the modified Bernoulli equation, an estimate of right atrial pressure (RAP) is added to the peak tricuspid regurgitant (TR) jet to approximate right ventricular systolic pressure (RVSP), which is equal to pulmonary arterial systolic pressure (PASP) in the absence of a pulmonary valve gradient.2 In spite of its widespread use, the accuracy and reproducibility of DE in estimating PASP have recently been questioned.3,4 The most common reason for discordant DE and RHC PASP results is inadequate TR jet signal. Some hemodynamic factors such as pulmonary capillary wedge (PCWP) were also proposed as a contributing factor for discordant results. However, until now, no study exists investigating the role of severe TR on agreement between Doppler 1
€ Ozpelit, et al.
and RHC PASP measurements. Severe TR is a common finding in patients with PAH, and it occurs secondarily to elevated pulmonary vascular resistance (PVR) and/or right ventricular (RV) dilatation. It is known that severe TR highly alters the hemodynamic interaction of right heart structures. In this study, we aimed to investigate whether severe TR has any impact on echocardiographic estimation of PASP. We hypothesized that the altered hemodynamic interaction of right heart structures in severe TR may severely contribute to the true estimation of PASP and RAP as well. Materials and Methods: Study Population: All consecutive RHCs, performed in pulmonary hypertension unit of DEU Hospital from January 1, 2010 to July 2013, were reviewed. Patients with mean PAP >25 mmHg at RHC and who underwent echocardiographic examination within the same hospitalization period were eligible for inclusion in this study. Exclusion criteria of the study were as follows: the presence of an insufficient quality of echo imaging, long-time interval between RHC and echo examination (>3 days), organic pathology of tricuspid valve on echocardiography including significant coaptation defect, minimal or no tricuspid regurgitant jet on echocardiography, left ventricular systolic dysfunction, more than moderate mitral and aortic valve disease, and uncorrected left-to-right shunts. Patients did not receive any specific PAH therapy, and no modification of actual diuretic therapy was made between TTE and RHC. Patients’ demographical, laboratory and clinical parameters, including BNP values, 6-minute walking distance (6MWD), etiology of pulmonary hypertension and functional class (FC), were recorded. Right Heart Catheterization: Right heart catheterization was performed at rest, without sedation, by an experienced cardiologist (BA). Measurements of PAP, RAP, and PCWP were taken at end-expiration. Cardiac output (Q) was measured by indirect Fick method with an assumed O2 consumption of the patient. Cardiac index (CI) was calculated as Q divided by body surface area. Pulmonary vascular resistance was calculated as mPAP minus left atrial pressure divided by Q. Transpulmonary gradient was calculated as the difference between mPAP and PCWP. Transthoracic Doppler Echocardiography: All patients had a comprehensive two-dimensional DE protocol within the same hospitalization
2
period with RHC, as described previously. Echocardiograms were performed by two experienced € using a Philips HD 11 cardiologists (BA and EO) XE machine with a 3.2-MHz transducer (Philips, Andover, MA, USA). Standard two-dimensional echocardiographic measurements were carried out according to recommendations of the American Society of Echocardiography.5 The left atrial (LA) and right atrial (RA) areas were traced manually and measured at end-systole from the twodimensional apical four-chamber view. RV internal end-diastolic diameter (apical four-chamber view), RV wall thickness (subcostal view), and right ventricular fractional area change (RFAC) were also obtained during 2D examination. Right ventricular fractional area change (RFAC) was calculated as RV end-diastolic area (RVEDA) minus RV end-systolic area (RVESA) divided by RVEDA in which measurements were obtained from apical four-chamber view.6 At apical four-chamber view, M-mode recording of the long axis was taken from the lateral side of the tricuspid annulus. The maximal distance of endocardial motion during systolic phase was defined as TAPSE.6 Mitral and tricuspid flow (TF) velocities were obtained with the sample volume placed at the tip of the mitral and tricuspid valve leaflets, respectively. The presence of valvular regurgitation was determined by color Doppler echocardiography. Tricuspid regurgitation was mostly quantified by jet area as follows: mild TR = jet area 10 cm2. Vena contracta and effective regurgitant orifice area were also measured when available.7 Pulmonary artery flow velocity was recorded from the parasternal shortaxis view with the sample volume placed at the central position. Tricuspid regurgitation velocity signal was recorded in multiple views (tricuspid inflow, parasternal short-axis, and apical fourchamber) with continuous wave spectral Doppler. Using the highest obtainable maximum velocity from these Doppler profiles, peak TR gradient was determined using the modified Bernoulli equation [4 9 (tricuspid regurgitation velocity)2]. The inferior vena cava (IVC) was imaged from the subcostal view while patients were asked to rapidly inhale or “sniff” during imaging. Estimated RAP was determined from the IVC size and the inspiratory degree of IVC collapse as follows: IVC >2.5 cm with no inspiratory collapse = 20 mmHg, IVC size >2.5 cm with
