Systematic underutilisation of secondary preventive drugs in patients with acute coronary syndrome and reduced renal function

The high risk of recurrent events in patients with reduced renal function following an acute coronary syndrome (ACS) may in part be due to suboptimal secondary prevention. We aimed to describe the association between renal dysfunction and the prescription, initiation and persistent use of secondary prevention during the first year after a first ACS.

We identified all patients admitted to any Swedish coronary care unit for a first ACS between 2005 and 2010 (n = 77,432). In 75,129 patients, creatinine levels were available in order to obtain the estimated glomerular filtration rate (eGFR). Persistent use of prescribed drugs was determined for 1 year using the National Prescription Registry, with complete coverage of all prescribed and dispensed drugs in Sweden.

After adjustment for relative and absolute contraindications, compared to patients with eGFR ≥ 60 mL/min/1.73 m², patients with eGFR 30–59 had higher odds of not being prescribed acetylsalicylic acid (ASA; odds ratio [OR]: 1.56, 95% confidence interval [CI]: 1.47–1.67), statins (OR: 2.94, 95% CI: 2.86–3.13) or β-blockade (OR: 1.25, 95% CI: 1.18–1.32). Patients with eGFR 30–59 were more likely to discontinue treatment with ASA (hazard ratio [HR]: 1.59, 95% CI: 1.42–1.56), statins (HR: 1.35, 95% CI: 1.29–1.41), angiotensin-converting enzyme inhibitors and angiotensin-II receptor blockers (HR: 1.37, 95% CI: 1.31–1.43) or β-blockade (HR: 1.22, 95% CI: 1.18–1.27). Patients with eGFR < 30 showed a similar pattern in both prescription and discontinuation.

High-risk ACS patients with reduced renal function are less likely to be prescribed secondary prevention drugs at discharge, are less likely to initiate treatment when being prescribed these drugs, are less likely to be persistent in the use of these drugs and more often discontinue treatment.