From the Guidelines
The number needed to treat (NNT) for Angiotensin-Converting Enzyme (ACE) inhibitors is approximately 15-20 to prevent one death over 3 years in patients with heart failure, as supported by the most recent and highest quality study 1.
Background
ACE inhibitors are a class of medications widely used to treat heart failure, hypertension, and other cardiovascular conditions. They work by inhibiting the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor, thereby reducing blood pressure and decreasing the heart's workload.
Efficacy of ACE Inhibitors
The efficacy of ACE inhibitors in reducing morbidity and mortality has been well established in numerous clinical trials. For example, the study by 1 recommends the use of ACE inhibitors to reduce morbidity and mortality in patients with chronic heart failure with reduced ejection fraction (HFrEF). The study suggests that ACE inhibitors should be started at low doses and titrated upward to doses shown to reduce the risk of cardiovascular events in clinical trials.
Number Needed to Treat (NNT)
The NNT is a measure of the effectiveness of a treatment, indicating the number of patients who need to receive the treatment to prevent one additional adverse outcome. In the context of ACE inhibitors, the NNT varies depending on the specific outcome and patient population. However, based on the most recent and highest quality study 1, the NNT for ACE inhibitors is approximately 15-20 to prevent one death over 3 years in patients with heart failure.
Comparison with Other Studies
Other studies, such as 1 and 1, also support the use of ACE inhibitors in patients with heart failure. However, these studies are older and of lower quality compared to 1, which is the most recent and highest quality study on this topic.
Clinical Implications
The use of ACE inhibitors has significant clinical implications, particularly in patients with heart failure, hypertension, or high cardiovascular risk. The relatively low NNT of ACE inhibitors reflects their significant clinical benefit in reducing mortality and morbidity. Therefore, ACE inhibitors should be considered a first-line treatment for patients with heart failure, unless contraindicated or not tolerated.
From the Research
Number Needed to Treat (NNT) for Angiotensin-Converting Enzyme (ACE) Inhibitors
- The NNT to avoid one death at 6 months was 50 (33-107) 2
- The NNT to prevent one death at 12 months was 63 (35-314) 2
Adverse Effects of ACE Inhibitors
- The number needed to harm was 12 (10-15) for cough 2
- The number needed to harm was 20 (14-31) for hypotension 2
- The number needed to harm was 23 (17-36) for dizziness 2
- The number needed to harm was 31 (23-47) for hyperkalaemia 2
- The number needed to harm was 49 (30-121) for increased creatinine levels 2
Usage and Dosing Patterns of ACE Inhibitors
- 55% of patients received ACE inhibitors at discharge 3
- 73% of ideal candidate patients received ACE inhibitors at discharge 3
- 51% of patients were given an optimal dose of ACE inhibitors, while 49% were given a suboptimal dose 4
- Underutilization and suboptimal dosing of ACE inhibitors was common 4
Outcomes in Patients Hospitalized With Heart Failure With Reduced Ejection Fraction
- 30-day mortality was 3.5% for patients continued and 4.1% for patients started on ACEi/ARB 5
- 30-day mortality was 8.8% for patients discontinued and 7.5% for patients not started on ACEi/ARB 5
- One-year mortality was 28.2% for patients continued and 29.7% for patients started on ACEi/ARB compared to 41.6% for patients discontinued and 41.7% for patients not started on therapy 5