During a grand rounds presentation, a cardiologist discusses the findings of the recent VANGUARD trial, which evaluated the addition of a novel aldosterone synthase inhibitor to standard therapy in patients with resistant hypertension. The primary goal of the study was to assess the reduction in major adverse cardiovascular events (MACE) over 4 years.
The trial included 5,000 participants evenly divided into an intervention arm and a standard-care arm. The following event data were recorded during the follow-up period:
| Study Arm | Total Participants | MACE (Efficacy Endpoint) | Severe Hyperkalemia (Adverse Event) |
|---|---|---|---|
| Aldosterone Synthase Inhibitor | 2,500 | 175 | 100 |
| Standard Care | 2,500 | 300 | 50 |
A resident is asked to interpret the clinical impact of these findings for a patient considering the new therapy. Based on the provided data, what are the number needed to treat (NNT) to prevent one MACE and the number needed to harm (NNH) for severe hyperkalemia, respectively?
- ANNT = 5, NNH = 2
- BNNT = 14, NNH = 50
- CNNT = 20, NNH = 25
- NNT = 20, NNH = 50Answer
- ENNT = 25, NNH = 20
Answer
For efficacy (MACE):
- The baseline risk in the standard care group is ().
- The risk in the intervention group is ().
- The ARR is the difference between these risks: ().
- The NNT is the reciprocal of the ARR: . This means patients need to be treated with the aldosterone synthase inhibitor to prevent one additional MACE.
For harm (Severe Hyperkalemia):
- The risk in the intervention group is ().
- The baseline risk in the standard care group is ().
- The ARI is the difference: ().
- The NNH is the reciprocal of the ARI: . This means for every patients treated, one additional patient will develop severe hyperkalemia compared to standard care.