To determine the clinical significance of the occurrence of hemodynamic deterioration after the administration of calcium channel blocking drugs, nifedipine (20 mg orally) was administered to 29 patients with severe left ventricular dysfunction. Thirteen patients showed hemodynamic improvement with the drug (Group 1), as shown by a notable increase in cardiac index associated with a modest decrease in mean arterial pressure. The other 16 patients exhibited hemodynamic deterioration after nifedipine (Group 2), as reflected by a decline in right and left ventricular stroke work indexes accompanied by a marked hypotensive response. These differences were not related to differences in the peripheral vascular response to nifedipine, because both groups showed similar decreases in systemic and pulmonary vascular resistances. Groups 1 (hemodynamic improvement) and 2 (hemodynamic deterioration) were similar with respect to all demographic variables and pretreatment left ventricular performance (cardiac index, left ventricular filling pressure and systemic vascular resistance). Yet, the 1 year actuarial survival in patients in Group 1 was substan- tially better than that in patients in Group 2 (67 versus 23%, p = 0.009). Group 2, however, had higher values for plasma renin activity (17.7 ± 6.0 versus 4.3 ±1.4mg/ml per h, p <0.05), lower values for serum sodium concentration (134.6 ± 1.2 versus 139.2 ± 0.6 mEq/liter, p < 0.05) and higher values for mean right atrial pressure (15.8 ± 2.0 versus 7.9 ± 1.4 mm Hg, p < 0.01) than did patients in Group 1. Previous work has identified these three variables as important determinants of survival in patients with severe chronic heart failure; yet, the hemodynamic response to nifedipine was more powerful than any of these three variables in predicting long-term prognosis. These findings confirm the hypothesis that patients with the most advanced heart failure (as reflected by their poor long-term survival) are most likely to show hemodynamic deterioration after calcium channel blockade, and they suggest that the assessment of neurohormonal activation and right ventricular performance more accurately identifies such patients than do conventional measures of left ventricular performance.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine