Relative lymphocyte count: A prognostic indicator of mortality in elderly patients with congestive heart failure

Background: A reduction in the relative lymphocyte count is a marker of the stress response; however, its prognostic value remains undetermined. The objective of this study was to investigate the predictive value of the relative lymphocyte count for survival in elderly patients with congestive heart failure (CHF). Methods and Results: One thousand two hundred seventy-four consecutive patients above the age of 65 years hospitalized with heart disease were enrolled in the CHF Italian Study and followed up for 3 years. Of these, 413 patients were excluded because of factors that could affect the lymphocyte count. Of the remaining 861 patients, 423 (49%) met the criteria for the diagnosis of CHF (mean age 76 ± 7 years, 51% men), of whom 162 patients (38%) had a relative lymphocyte count ≤20%. The 3-year all-cause mortality in patients with CHF and a relative lymphocyte count ≤20% was 64% compared with 40% in patients with a relative lymphocyte count >20% (P < .0001). The age- and sex-adjusted hazard ratio for death in patients with CHF and low relative lymphocyte count was 1.76 (95% confidence interval 1.34-2.32, P = .0001). After adjustment for baseline differences and variables associated with or known to affect lymphocyte count, the hazard ratio remained significantly different from 1.0 (hazard ratio 1.73, 95% confidence interval 1.21-2.48, P = .0026). Conclusion: A low relative lymphocyte count is an independent marker of poor prognosis in elderly patients with CHF. The relative lymphocyte count is a simple, accurate, widely available, and inexpensive marker that can help to identify elderly patients with CHF who are at increased risk for mortality. The pathophysiologic mechanism of this observation remains to be determined.