Prognostication of post-infarct chronic heart failure: superiority of clinical assessment vs. cardiopulmonary and left ventricular function analysis.

BACKGROUND

Prognostication of congestive heart failure post-myocardial infarction (MI) is important for decision making. We sought of a head-to-head comparison between the prognostic implication of clinical, cardiopulmonary, and left ventricular (LV) function assessment.

METHODS

Retrospectively, 100 consecutive post-MI patients (MI history 1418+/-1668 days ago) were stratified by NYHA functional classification system, cardiopulmonary exercise testing (CPX) [oxygen consumption at maximal exercise (VO(2max)) and at the anaerobic threshold (VO(2AT)) resulting in the Weber classification], and LV function analysis by M-mode and two-dimensional echocardiography [LV end-diastolic and -systolic diameter index (LVDDI and LVSDI), shortening fraction (%D), and LV end-diastolic and -systolic volume index (EDVI and ESVI), LV ejection fraction (EF)]. Patients were controlled by phone call 1470+/-607 days later.

RESULTS

There was only a modest correlation between NYHA and Weber classes (r=0.402) and no correlation between VO(2max) and ESVI (r=0.080) nor between NYHA and ESVI (r=0.174). Several parameters (ESVI, LVDDI, LVSDI, %D) could discriminate NYHA classes to a higher significance (p=0.05; 0.0008; 0.0002; 0.04) than the Weber classes (n.s.; p=0.03; n.s.; n.s.). The following parameters could significantly differentiate quartiles in a log-rank analysis (Kaplan-Meier survival curves): NYHA classes (p=0.0001), Weber classes (p=0.069), EDVI (p=0.004), ESVI (p=0.0001), EF (p=0.002), LVDDI (p=0.002), LVSDI (p<0.001) and %D (p<0.001). Multivariate analysis isolated the following three parameters implying decreasing, independent prognostic information: NYHA classes (p=0.001), ESVI (p=0.003), and Weber classes (p=0.040).

CONCLUSIONS

In post-MI patients the thorough clinical assessment according the NYHA functional classification system implies higher prognostic information than more objective measures. This should be considered especially in primary care and should lessen the dependence on costly and expertise-dependent technical investigations.