Serum Albumin was Associated with a Long Term Cardiovascular Mortality among Elderly Patients with Stable Coronary Artery Disease

Abstract

Background: Serum albumin (SA), a multifunction protein, contributes to maintaining a variety of physiological functions. Studies have linked SA to atherosclerosis with possible mechanisms including a response to inflammation. The contribution of albumin to cardiovascular (CV) mortality in elderly patients with stable coronary artery disease (CAD) remains unclear.

Methods: We investigated 321 elderly patients with stable CAD undergoing coronary angiography between 2003 and 2006. CV mortality data were obtained from the National Registry of Deaths in Taiwan. CV mortality included deaths attributable to ischemic heart disease, congestive heart disease, and stroke. The association between baseline SA and CV mortality was assessed using a Cox model and Fine-Gray model when non-CV mortality was considered a competing event.

Results: During a median follow-up of 97 months, 39 (12.1%) participants died from CV disease and 76 (23.7%) died from non-CV diseases. After adjusting for covariates, patients in the SA ≥ 3.75 g/dL group had a lower frequency of CV mortality compared with those in the SA < 3.75 g/dL group [hazard ratio (HR): 0.20; 95% confidence interval (CI): 0.08-0.49; p < 0.001]. Similarly, compared to the participants with non-CV mortality, the SA ≥ 3.75 g/dL group had a lower frequency of CV mortality compared with the SA < 3.75 g/dL group (subdistribution HR: 0.27; 95% CI: 0.11-0.65; p < 0.001) in adjusted competing risk models.

Conclusions: A SA level ≥ 3.75 g/dL at admission was associated with decreased long-term CV mortality and may be useful for risk prediction in elderly patients with stable CAD.

Keywords: Aging; Coronary artery disease (CAD); Serum albumin (SA).

Figure 1

Flow chart of study subjects. CAD, coronary artery disease; NSTEMI, non-ST elevation myocardial infarction; STEMI, ST elevation myocardial infarction.

Figure 2

Kaplan-Meier curves for CV mortality between SA (≥ and < 3.75 g/dL) subgroups. Kaplan-Meier curves show significant differences in the incidence of events between two groups (log-rank test, p < 0.001). CV, cardiovascular; SA, serum albumin.

Figure 3

Temporal changes in time-dependent area under the receiver operating characteristics (ROC) curve analysis for CV mortality. (A) Baseline model (AUC: 0.76). (B) Baseline model + SA (≥ and < 3.75 g/dL), (AUC: 0.84). AUC, area under curve; CV, cardiovascular; SA, serum albumin.