European Heart Journal (1990) 11,441 -446
Does left ventricular aneurysm influence survival after acute myocardial infarction? M. HERAS, G. SANZ, A. BETRIU, L. MONT, T. DE FLORES AND F. NAVARRO-LOPEZ
Cardiovascular Division, Department of Medicine, Hospital Clinic i Provincial, University of Barcelona, Spain KEY WORDS: Left ventricular aneurysm, postinfarct prognosis. To test whether left ventricular aneurysm independently influences survival after acute myocardial infarction, a series of 386 consecutive men aged60 years or less, were followedup for 57(40-100) months. Catheterization was performed 1 month following the infarct. Aneurysm, defined as a diastolic outward bulging with akinetic or dyskinetic systolic motion, was diagnosed in 52 patients (13-5%). Mortality was higher (29% vs 14%; P < 0-02) in patients with left ventricular aneurysm; their probability ofsurvival at 60 months was 75%vs90% in patients without aneurysm. Cox regression analysis for the whole population identified ejection fraction, bifascicular block, number of diseased vessels and angina after infarction as the only independent predictors of survival; when adjusted for these variables, differences in mortality between patients with and without aneurysm were no longer significant. To investigate further the role of aneurysm in survival, the 52 patients presenting with left ventricular aneurysm were matched with 52 of the remaining 334 patients according to the following baseline variables: ejection fraction, number of diseased vessels, left ventricular end-diastolic pressure, and bifascicular block. The survival curves of these two subsets were similar (mortality rates of 75% and 82%, respectively). Cox regression analysis of the whole cohort of 104 patients selected bifascicular block and the number of diseased vessels, but not left ventricular aneurysm, as independent predictors of outcome.
Introduction
surgery, not for symptomatic relief, but to improve prognosis.
Left ventricular aneurysm after transmural myocardial infarction has generally been associated with a poor prognosis1'"4'. Severe ventricular arr h y t h m i a s ^ , thromboembolic phenomena' 3 ^ and, particularly, c o n g e s t s heart failure"^"" may well account for an unfavourable outcome. However, ,t remains controvert if life expectancy
Methods P A T I E N T po P U L A T 1 O N F r o m December ,975 t0 Feb ^ ^ of ^ ma,e Jents ^ tQ o u f c o r Q unk wkh
left ve tncular aneur s 1 Patien,tSZ! " y " ? 1S p threatened because of the aneurysm itself or
tion. Patients came to the hospital either by them^ of w e r e refefred thdr n
?* a " S e ,° f . F w
" " " " f / f ' eft . ve 1l5f C S r
function'- • after myocardial .nfarct,on>'3'. The present study was therefore undertaken.to ascertain whether left ventncular aneurysm has independent prognostic significance If so, we would be able to identify those patients who are ike y to benefit from }
v
J
,98,
a tota,
rdia,
infarc.
^
^
^
for evaluation of chest pain. Patients referred for treatment
of
^ ^
an(J 3 5
jents w£re
^ ^
refusa,
complications were
acute
exduded
were
^ ^ ^ ^ ^ ^
[n t h e a c u t e from
^
for en
of
for
. .. ,. r ., . . ,. .... coexisting life-threatening non-cardiac conditions
submitted for publication on 3 January 1989 and m rcvi«d form ^ ^ patients). The remaining 403 patients underio August 1989. went cardiac catheterization, and 386 of them had Presented in pan .1 .he 37th Annual Scientific Session of the American angiogramS judged adequate for analysis. A left College of Cardiology, March 27-31,1988. ventricular aneurysm, as defined below, was found Address for reprints: M.gd, Heras, M.D., Cardiovascular D,vision, i n 5 2 P a t i e n t S ( 1 3 5 % ) who form the Study gTOUp. Hospital Oinic i Provincial, Villarroel 170, Barcelona 08036, Spain. N o pathologic Or echocardiographic Studies were 0195-668X, 90/050441+06 $03.00/0 Downloaded from https://academic.oup.com/eurheartj/article-abstract/11/5/441/422964 by INSEAD user on 22 July 2018
C 1990 The European Society of Cardiology
442 M. Heras et al.
performed in those 24 patients who died before cardiac catheterization.
CRITERIA FOR INFARCTION
The criteria for infarction included at least two of the following: ischaemic chest pain lasting more than 20 min; typical rise and fall of cardiac enzymes, and evolving Q-wave abnormalities with acute ST-segment and Q-wave changes on the electrocardiogram. Previous myocardial infarction was diagnosed if the patient had previously been admitted for a documented myocardial infarction or if the Q wave in the electrocardiogram was diagnostic of a pre-existing infarct.
STUDY PROTOCOL
A detailed description of the study protocol has been published elsewhere'1415'. The study was approved by the Committee for Human Research at our institution. Informed consent was obtained for all patients. Four weeks after infarction, combined right and left heart catheterization was performed and cardiac output was measured by the Fick method. Single plane (30° right anterior oblique view) left ventricular angiography and selective left and right coronary arteriography in multiple views are obtained. Left ventricular aneurysm was defined as an outward diastolic bulging showing akinetic or dyskinetic systolic motion. This was in contrast to localized areas of dyskinesis in which the alteration in ventricular contour occurred only during systole. Aneurysms were classified as anterior, apical or posterior, or a combination of more than one of these areas. Left ventricular ejection fraction was measured by the area-length method for single plane calculations'161. Residual ejection fraction was determined after exclusion of the aneurysm area, as proposed by Watson'171. Calculation of the percent abnormally contracting segments was made by measuring the percentage of the end-diastolic silhouette that was either akinetic or dyskinetic1'81. All angiograms were reviewed by two independent observers. Patients were seen monthly during the first 3 months and every 3rd month thereafter. Clinical status, physical findings and resting electrocardiogram were recorded at each visit. Surgical treatment was confined to intractable angina or lesions of the left main coronary artery. Mean (±SD) follow-up was 57±29 (range 40-100) months.
STATISTICAL ANALYSIS
Three different approaches were used for statistical analysis. First, a total of 79 variables from the clinical history, physical examination, haemodynamic, angiographic, and follow-up data were identified in each patient'141. These variables were examined by univariate statistical methods to determine differences between those who did and did not develop left ventricular aneurysms. Student's f-test, Fischer's exact test, and the chi-square test were utilized when appropriate. To identify variables independently predictive of survival, multivariate analysis with the Cox's technique was applied in a stepwise manner to variables reaching significance in the univariate analysis. Then we calculated the estimated survival function adjusting for ejection fraction, number of diseased vessels and bifascicular block. Second, we constructed Kaplan-Meier's actuarial curves to approximate life expectancy of patients with and without left ventricular aneurysm. Patients who underwent surgical revasculanzation were considered censored observations at the time of surgery. Finally, to investigate further the role of left ventricular aneurysm in survival, we matched the 52 patients with aneurysm with 52 of the remaining 334 patients according to the following variables: left ventricular end-diastolic pressure, number of diseased vessels, bifascicular block and ejection fraction. The first three variables used for matching had been identified as the independent predictors of mortality for the patients with aneurysm (unpublished data). After constructing the actuarial curves of the two groups we performed a multivariate Cox's regression analysis of the 104 patients to test the correlation of all matching variables, plus the presence of left ventricular aneurysm, with mortality. All statistical analysis were done using the BMDP program, except for matching, which was performed with the SPSS program. Results Prevalence of left ventricular aneurysm in this series was 13-5% (52/386). As shown in Table 1. patients with left ventricular aneurysm were older, had a higher incidence of previous myocardial infarction and anterior wall infarcts and a higher degree of left ventricular impairment. Patients in the matched group were similar to patients with aneurysm except that the latter had a higher degree
Downloaded from https://academic.oup.com/eurheartj/article-abstract/11/5/441/422964 by INSEAD user on 22 July 2018
L V aneurysm and survival 443
Table I Variables of statistical significance to establish in univariate analysis differences between patients with and without left ventricular aneurysm LV aneurysm (n = 52) Age (years) Previous MI Anterior wall MI Dyslipaemia Killip Class IV PeakCK(IU) LVEDP(mmHg) PAP (mmHg) Global EF (%) Residual EF(%) %ACS
No aneurysm (n = 324)
53±6
5O±7
10(19%) 37(71%) 33 (63%) 7(13%) 1336 ±828
24 (7%) 113(33%) 113(33%) 5 (1%) 1045 ±767
17±8 19±7 33±12 45 ±14 35±12
13±6 15±5 48±14 50±I2 11±13
P value
Does left ventricular aneurysm influence survival after acute myocardial infarction? M. HERAS, G. SANZ, A. BETRIU, L. MONT, T. DE FLORES AND F. NAVARRO-LOPEZ
Cardiovascular Division, Department of Medicine, Hospital Clinic i Provincial, University of Barcelona, Spain KEY WORDS: Left ventricular aneurysm, postinfarct prognosis. To test whether left ventricular aneurysm independently influences survival after acute myocardial infarction, a series of 386 consecutive men aged60 years or less, were followedup for 57(40-100) months. Catheterization was performed 1 month following the infarct. Aneurysm, defined as a diastolic outward bulging with akinetic or dyskinetic systolic motion, was diagnosed in 52 patients (13-5%). Mortality was higher (29% vs 14%; P < 0-02) in patients with left ventricular aneurysm; their probability ofsurvival at 60 months was 75%vs90% in patients without aneurysm. Cox regression analysis for the whole population identified ejection fraction, bifascicular block, number of diseased vessels and angina after infarction as the only independent predictors of survival; when adjusted for these variables, differences in mortality between patients with and without aneurysm were no longer significant. To investigate further the role of aneurysm in survival, the 52 patients presenting with left ventricular aneurysm were matched with 52 of the remaining 334 patients according to the following baseline variables: ejection fraction, number of diseased vessels, left ventricular end-diastolic pressure, and bifascicular block. The survival curves of these two subsets were similar (mortality rates of 75% and 82%, respectively). Cox regression analysis of the whole cohort of 104 patients selected bifascicular block and the number of diseased vessels, but not left ventricular aneurysm, as independent predictors of outcome.
Introduction
surgery, not for symptomatic relief, but to improve prognosis.
Left ventricular aneurysm after transmural myocardial infarction has generally been associated with a poor prognosis1'"4'. Severe ventricular arr h y t h m i a s ^ , thromboembolic phenomena' 3 ^ and, particularly, c o n g e s t s heart failure"^"" may well account for an unfavourable outcome. However, ,t remains controvert if life expectancy
Methods P A T I E N T po P U L A T 1 O N F r o m December ,975 t0 Feb ^ ^ of ^ ma,e Jents ^ tQ o u f c o r Q unk wkh
left ve tncular aneur s 1 Patien,tSZ! " y " ? 1S p threatened because of the aneurysm itself or
tion. Patients came to the hospital either by them^ of w e r e refefred thdr n
?* a " S e ,° f . F w
" " " " f / f ' eft . ve 1l5f C S r
function'- • after myocardial .nfarct,on>'3'. The present study was therefore undertaken.to ascertain whether left ventncular aneurysm has independent prognostic significance If so, we would be able to identify those patients who are ike y to benefit from }
v
J
,98,
a tota,
rdia,
infarc.
^
^
^
for evaluation of chest pain. Patients referred for treatment
of
^ ^
an(J 3 5
jents w£re
^ ^
refusa,
complications were
acute
exduded
were
^ ^ ^ ^ ^ ^
[n t h e a c u t e from
^
for en
of
for
. .. ,. r ., . . ,. .... coexisting life-threatening non-cardiac conditions
submitted for publication on 3 January 1989 and m rcvi«d form ^ ^ patients). The remaining 403 patients underio August 1989. went cardiac catheterization, and 386 of them had Presented in pan .1 .he 37th Annual Scientific Session of the American angiogramS judged adequate for analysis. A left College of Cardiology, March 27-31,1988. ventricular aneurysm, as defined below, was found Address for reprints: M.gd, Heras, M.D., Cardiovascular D,vision, i n 5 2 P a t i e n t S ( 1 3 5 % ) who form the Study gTOUp. Hospital Oinic i Provincial, Villarroel 170, Barcelona 08036, Spain. N o pathologic Or echocardiographic Studies were 0195-668X, 90/050441+06 $03.00/0 Downloaded from https://academic.oup.com/eurheartj/article-abstract/11/5/441/422964 by INSEAD user on 22 July 2018
C 1990 The European Society of Cardiology
442 M. Heras et al.
performed in those 24 patients who died before cardiac catheterization.
CRITERIA FOR INFARCTION
The criteria for infarction included at least two of the following: ischaemic chest pain lasting more than 20 min; typical rise and fall of cardiac enzymes, and evolving Q-wave abnormalities with acute ST-segment and Q-wave changes on the electrocardiogram. Previous myocardial infarction was diagnosed if the patient had previously been admitted for a documented myocardial infarction or if the Q wave in the electrocardiogram was diagnostic of a pre-existing infarct.
STUDY PROTOCOL
A detailed description of the study protocol has been published elsewhere'1415'. The study was approved by the Committee for Human Research at our institution. Informed consent was obtained for all patients. Four weeks after infarction, combined right and left heart catheterization was performed and cardiac output was measured by the Fick method. Single plane (30° right anterior oblique view) left ventricular angiography and selective left and right coronary arteriography in multiple views are obtained. Left ventricular aneurysm was defined as an outward diastolic bulging showing akinetic or dyskinetic systolic motion. This was in contrast to localized areas of dyskinesis in which the alteration in ventricular contour occurred only during systole. Aneurysms were classified as anterior, apical or posterior, or a combination of more than one of these areas. Left ventricular ejection fraction was measured by the area-length method for single plane calculations'161. Residual ejection fraction was determined after exclusion of the aneurysm area, as proposed by Watson'171. Calculation of the percent abnormally contracting segments was made by measuring the percentage of the end-diastolic silhouette that was either akinetic or dyskinetic1'81. All angiograms were reviewed by two independent observers. Patients were seen monthly during the first 3 months and every 3rd month thereafter. Clinical status, physical findings and resting electrocardiogram were recorded at each visit. Surgical treatment was confined to intractable angina or lesions of the left main coronary artery. Mean (±SD) follow-up was 57±29 (range 40-100) months.
STATISTICAL ANALYSIS
Three different approaches were used for statistical analysis. First, a total of 79 variables from the clinical history, physical examination, haemodynamic, angiographic, and follow-up data were identified in each patient'141. These variables were examined by univariate statistical methods to determine differences between those who did and did not develop left ventricular aneurysms. Student's f-test, Fischer's exact test, and the chi-square test were utilized when appropriate. To identify variables independently predictive of survival, multivariate analysis with the Cox's technique was applied in a stepwise manner to variables reaching significance in the univariate analysis. Then we calculated the estimated survival function adjusting for ejection fraction, number of diseased vessels and bifascicular block. Second, we constructed Kaplan-Meier's actuarial curves to approximate life expectancy of patients with and without left ventricular aneurysm. Patients who underwent surgical revasculanzation were considered censored observations at the time of surgery. Finally, to investigate further the role of left ventricular aneurysm in survival, we matched the 52 patients with aneurysm with 52 of the remaining 334 patients according to the following variables: left ventricular end-diastolic pressure, number of diseased vessels, bifascicular block and ejection fraction. The first three variables used for matching had been identified as the independent predictors of mortality for the patients with aneurysm (unpublished data). After constructing the actuarial curves of the two groups we performed a multivariate Cox's regression analysis of the 104 patients to test the correlation of all matching variables, plus the presence of left ventricular aneurysm, with mortality. All statistical analysis were done using the BMDP program, except for matching, which was performed with the SPSS program. Results Prevalence of left ventricular aneurysm in this series was 13-5% (52/386). As shown in Table 1. patients with left ventricular aneurysm were older, had a higher incidence of previous myocardial infarction and anterior wall infarcts and a higher degree of left ventricular impairment. Patients in the matched group were similar to patients with aneurysm except that the latter had a higher degree
Downloaded from https://academic.oup.com/eurheartj/article-abstract/11/5/441/422964 by INSEAD user on 22 July 2018
L V aneurysm and survival 443
Table I Variables of statistical significance to establish in univariate analysis differences between patients with and without left ventricular aneurysm LV aneurysm (n = 52) Age (years) Previous MI Anterior wall MI Dyslipaemia Killip Class IV PeakCK(IU) LVEDP(mmHg) PAP (mmHg) Global EF (%) Residual EF(%) %ACS
No aneurysm (n = 324)
53±6
5O±7
10(19%) 37(71%) 33 (63%) 7(13%) 1336 ±828
24 (7%) 113(33%) 113(33%) 5 (1%) 1045 ±767
17±8 19±7 33±12 45 ±14 35±12
13±6 15±5 48±14 50±I2 11±13
P value
