Prior antiplatelet use and cardiovascular outcomes in patients presenting with acute coronary syndrome

Antiplatelet (AP) therapy remains the mainstay of therapy in post-acute coronary syndrome (ACS) patients, however, the impact of prior antiplatelet (PAP) use and their outcomes remains controversial. This study aimed to find out whether patients who were on PAP use is associated with better cardiovascular (CV) outcomes post ACS compared to those with no antiplatelet (NAP) use.

Patients with ACS and admitted to Hospital Serdang from 1st of January to 31st of December 2016 were recruited through consecutive sampling. Patients were categorized into whether they were PAP use or NAP. Patients characteristics and CV events were analyzed and compared. Cardiovascular events include a composite of ACS, stroke, stent thrombosis or death. Logistic regression was used to compare CV events between PAP and NAP use.

A total of 440 patients were included. Of these, 34.7% (n=153) of patients had PAP while 65.3% (n= 287) NAP use. Patients with PAP were significantly older, and more likely to have co-morbidities than NAP group. Cardiovascular event during hospitalization was similar between two groups (OR 0.41; 95% CI 0.13–1.21; p=0.094), but higher in PAP group after discharge (OR 1.76; 95% CI 1.09–2.85; p=0.022). After adjustment for relevant covariates, PAP use was not an independent predictor for CV event after discharge (adjusted OR 0.87; 95% CI 0.43–1.76; p=0.696).

After an ACS, we found that PAP and NAP use have similar risk of CV events during hospitalisation and after discharge.