Treatment optimization of angiotensin converting enzyme inhibitors and associated factors in Ayder Comprehensive Specialized Hospital: a cross-sectional study

Background: Angiotensin-converting enzyme inhibitors have morbidity and mortality benefits in heart failure. Failure to optimize treatment using these medications increases hospitalizations, worsens signs and symptoms of heart failure, and reduces the overall treatment outcome. Therefore, the main purpose of this study was to assess the practice of treatment optimization of these medications and associated factors.

Results: A hospital-based cross-sectional study was conducted on 61 ambulatory heart failure patients, recruited using a convenience sampling technique, from February 25 to May 24, 2016 at the cardiology clinic of Ayder Comprehensive Specialized Hospital. Descriptive, inferential and Kaplan-Meier 'tolerability' analyses were employed. All patients were taking only enalapril as part of their angiotensin converting enzyme inhibitor treatment. According to the 2013 American College of Cardiology/American Heart Association guideline, about fourth-fifth (80.3%) of the patients were tolerating to the hypotensive effect of enalapril. The dose of enalapril was timely titrated (every 2-4 weeks) and was optimized for only 11.5 and 27.8% of the patients, respectively. Considering the tolerance, timely titration, and dose optimization, only 3.3% of the overall enalapril treatment was optimized. Multivariate regression results showed that the odds of having timely titration of enalapril for patients who were taking enalapril and calcium channel blockers were almost 20 times [adjusted odds ratio (AOR) = 21.68, 95% confidence interval (CI) 1.23-383.16, p < 0.036] more compared to patients who were taking enalapril and β-blockers. A Log Rank Chi Square result showed a 19.42 magnitude of better toleration of enalapril (p < 0.001) for patients who were taking enalapril for more than 1 year compared to less than a year.

Conclusion: This study provides a platform for assessment of the treatment optimization practice of enalapril, which remains the pressing priority and found to be poor in the ambulatory setting, despite a better tolerability to the hypotensive effect of enalapril. We call for greater momentum of efforts by health care providers in optimizing the treatment practice to benchmark with other optimization practices.