Impact of Prior Use of Four Preventive Medications on Outcomes in Patients Hospitalized for Acute Coronary Syndrome--Results from CPACS-2 Study

BACKGROUND: It is widely reported that long-term use of four preventive medications (antiplatelet agents, angiotensin converting enzyme inhibitor / angiotensin receptor blocker, statin and beta-blockers) reduce the risk of subsequent acute coronary syndromes (ACS). It is unclear whether these four medications benefit patients who develop ACS despite its use. METHODS AND RESULTS: Logistic regression and propensity-score was applied among 14790 ACS patients to assess the association between prior use of four preventive medications and in-hospital outcomes including severity of disease at presentation (type of ACS, systolic blood pressure <90 mmHg, and heart rate> = 100 beats/min), complicating arrhythmia and major adverse cardiovascular events (MACEs, including all deaths, non-fatal myocardial infarction or re-infarction, and non-fatal stroke). Prior use of each of the four medications was significantly associated with less severity of disease (ORs ranged from 0.40 to 0.82, all P<0.05), less arrhythmia (ORs ranged from 0.45 to 0.64, all P<0.05), and reduced risk of MACEs (ORs ranged from 0.59 to 0.73, all P<0.05) during hospitalization. Multiple variable-adjusted ORs of MACEs were 0.77, 0.67, 0.48 and 0.59 respectively in patients with 1, 2, 3 and 4 medications in comparison with patients with none, and other clinical outcomes showed the same trend (P for trend < 0.05). CONCLUSIONS: Among ACS patients in our study, those with prior use of four preventive medications presented with less disease severity, developed less arrhythmia and had a lower risk of in-hospital MACEs. The value of taking these medications may beyond just preventing occurrence of the disease.