Long-term secondary prevention and outcome following acute coronary syndrome: real-world results from the Swedish Primary Care Cardiovascular Database.

Abstract

Most studies of treatment adherence after acute coronary syndrome (ACS) are based on prescribed drugs and lack long-term follow-up or consecutive data on risk factor control. We studied the long-term treatment adherence, risk factor control, and its association to recurrent ACS and death. We retrospectively included 3765 patients (mean age 75 years, 40% women) with incident ACS from 1 January 2006 until 31 December 2010 from the Swedish Primary Care Cardiovascular Database of Skaraborg. All patients were followed until 31 December 2014 or death. We recorded blood pressure (BP), low-density lipoprotein cholesterol (LDL-C), recurrent ACS, and death. We used data on dispensed drugs to calculate the proportion of days covered for secondary prevention medications. Cox regressions were used to analyse the association of achieved BP and LDL-C to recurrent ACS and death. The median follow-up time was 4.8 years. The proportion of patients that reached BP of <140/90 mm Hg was 58% at Year 1 and 66% at Year 8. 65% of the patients reached LDL-C of <2.5 mmol/L at Year 1 and 56% at Year 8; however, adherence to statins varied from 43% to 60%. Only 62% of the patients had yearly measured BP, and only 28% yearly measured LDL-C. Systolic BP was not associated with a higher risk of recurrent ACS or death. Low-density lipoprotein cholesterol of 3.0 mmol/L was associated with a higher risk of recurrent ACS {hazard ratio [HR] 1.19 [95% confidence interval (CI) 1.00-1.40]} and death HR [1.26 (95% CI 1.08-1.47)] compared with an LDL-C of 1.8 mmol/L. This observational long-term real-world study demonstrates low drug adherence and potential for improvement of risk factors after ACS. Furthermore, the study confirms that uncontrolled LDL-C is associated with adverse outcome even in this older population.