ANTIPLATELET THERAPY IN PRIMARY PREVENTION. OBSERVATIONAL STUDY AND SURVIVAL ANALYSIS IN HIGH CARDIOVASCULAR RISK PATIENTS.

Abstract

Objective: Cardiovascular diseases are the leading cause of morbidity and mortality in industrialized countries. This was a retrospective observational study, evaluating clinical outcomes, metabolic consequences and survival rate resulting from prolonged antiplatelet therapy for primary prevention in patients with high CVR. Design and method: Overall, 516 patients were randomly selected from cardiovascular risk and metabolism consultations in a single center in Porto (Portugal). Sociodemographic, lifestyle and clinical characteristics were collected at baseline, including biochemical parameters, vascular risk scores and tests for heart and cardiovascular evaluation. In this follow-up with a median of 11 years, 287 patients received adjuvant antiplatelet therapy in primary prevention. Association between sex, observation time and treatments with LDLc and HDLc variations were assessed. Multiple linear regression was performed to evaluate which factors could explain the differences in HDLc and LDLc levels. Kaplan-Meier survival analysis was also conducted. Results: Therapy with statins was initiated early for metabolic compensation of dyslipidemia, according to clinical practice. Statistically significant reductions were found for almost all biochemical parameters, mean carotid intima-media thickness and lipid metabolism parameters, including triglycerides, total cholesterol and the respective fractions. Patients taking statins showed greater increased HDLc values and reduced LDLc values than those who were not. Additionally, women showed a more favorable evolution regarding HDLc increase compared to men. Survival rate was estimated at 77.5% with 22 years as the maximum observed time. The median time of survival was not computed, since more than half of the patients (77.5%) were alive after 22 years. No bleeding episodes were recorded during this long period of observation.In fact, 99.0% of patients were alive after 10 years and the percentage of patients alive remained over 90% at 17 years. After 18 years of observation, 88.6% of patients were alive, and at 20 years 77.5% were alive without major cardiovascular events (MACE). Conclusions: Antiplatelet therapy should always be considered in primary prevention in patients with high CVR. There were no cases of hemorrhage or MACE. The survival rate estimated for the study population was 77.5% over 22 years.