Association of blood pressure and its evolving changes with the survival of patients with heart failure.J Card Fail. 2008 Sep; 14(7):561-8.JC
The association between low blood pressure (BP) levels and increased mortality has been established in several studies of heart failure (HF). Although many drugs administered to these patients decrease BP, the relationship between changes in BP and survival has not been investigated. Nor have previous analyses distinguished among different forms of death. We investigated the influence of baseline BP and changes in BP during a 1-year period on the survival of patients with HF, distinguishing among sudden cardiac death, nonsudden cardiac death, and noncardiac death. We also identified the possible relationship with the baseline values of and changes in other clinical and treatment variables, including pharmacologic treatments.
METHOD AND RESULTS
A total of 1062 patients with chronic HF included in the Spanish National Registry of Sudden Death (mean age of 64.5 +/- 11.8 years, 72% were men, and 21% were in New York Heart Association class III with a mean left ventricular ejection fraction of 36.7% +/- 14.2%) were prospectively investigated for a mean of 1.9 +/- 0.6 years. A multivariable Cox proportional hazards model adjusting for clinical and therapeutic variables showed an independent association between low baseline systolic blood pressure (SBP) and nonsudden cardiac death (hazard ratio [HR] 0.96, 95% confidence interval [CI] 0.93-0.98), but changes in SBP during the following year did not influence survival, regardless of the baseline SBP level (P = .55). Contrariwise, baseline diastolic BP was not associated with mortality, but an increase in diastolic BP during the following year showed a borderline independent significant association with lower nonsudden cardiac death (HR 0.90, 95% CI 0.82-1.00). Treatment with angiotensin-converting enzyme inhibitors or beta-blockers at baseline was also associated with lower nonsudden cardiac mortality, as was an increase in left ventricular ejection fraction during the following year (HR 0.69, 95% CI 0.51-0.93; P = .015).
Among patients with stable HF, low SBP is associated with a greater risk of nonsudden cardiac death. The change in SBP during a 1-year period has no prognostic value. Because the beneficial effects of drugs associated with increased survival (in this study, angiotensin-converting enzyme inhibitors and beta-blockers) thus seem to be independent of their effects on BP, changes in BP should probably not influence the decision to use such drugs or continue their administration.