Platelet aggregation is significantly associated with cardiovascular mortality in elderly patients

Abstract

Background: The relationship between cardiovascular mortality and platelet function in elderly patients remains unclear.Methods: The outcomes for 347 consecutive patients aged 60 or older (mean age 77.5 years; 161 men and 186 women) who were treated without antiplatelet drugs on registration, were retrospectively studied after platelet aggregatability tests. The grading curve (GC) type, as an index of platelet aggregatability, was determined with an aggregometer and adenosine‐5′‐diphosphate as an agonist. Patients were classified into three groups according to GC type: Group I with suppressed aggregation (n = 40); Group II, normal aggregation (n = 208); and Group III, increased aggregation (n = 99). The mean follow‐up was 3.9 years.Results: There were three deaths in Group I, 33 in Group II, and 30 in Group III. The mean annual mortality rate was 2.1% in Group I, 4.0% in Group II and 7.5% in Group III. Although the most common cause of death was pneumonia in all three groups, the annual mortality rates due to vascular events were 0.7% in Group I, 0.6% in Group II and 4.2% in Group III. Cox proportional hazards models for vascular death yielded a hazard ratio of 1.5 in the increased GC type.Conclusion: These findings indicated that elderly patients with accelerated aggregation had higher mortality rates due to vascular events. Therefore, accelerated aggregation in the elderly suggested not only the progress of arteriosclerosis, but indications of antiplatelet therapy to prevent vascular events.