Multivariate statistical evaluation of intraaortic counterpulsation in pump failure complicating acute myocardial infarction

Abstract

Clinical and hemodynamic data from 189 patients sustaining an acute myocardial infarction complicated by pump failure were analyzed with a multivariate analysis method using correspondence analysis. A graphic decision-making system based on survival at 1 month was derived from a set of 101 patients. According to the scatter of patient data points on the factorial plane resulting from analysis, survival and nonsurvival zones were defined, and the position of a given patient within these zones was considered a reliable estimate of likelihood of survival. Then, the decision-making rule was applied to a set of 88 patients. Every new patient whose data fell within the nonsurvival zone was referred for consideration of intraaortic Counterpulsation. Thus, 43 patients were predicted to be nonsurvivors; 26 of these (group I) underwent balloon counterpulsation; the remaining 17 formed group II. The two groups were considered comparable. Seven patients in group I and none in group II survived for more than 1 month (probability [p] = 0.02); it was concluded that counterpulsation improves short-term survival. The analysis of baseline measurements demonstrated that a good prediction of short-term survival was feasible in the patients undergoing circulatory assistance. Thus, patients who are salvaged in these circumstances are probably in a less severe condition than others and mechanical assistance may not be of value in every patient predicted to be a nonsurvivor. Of the seven shortterm survivors, only three survived for more than 1 year. This low long-term survival rate (11 percent) was related to extensive myocardial and coronary arterial lesions found on angiography in survivors as well as in counterpulsation-dependent patients.