When RAS inhibitor use in males was further divided as use of angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARB), ACE inhibitors showed a non-significant tendency toward lower HF readmissions (HR 0.34, 95% CI 0.04–2.77), whereas the significant benefit persisted with ARBs (HR 0.19, 95% CI 0.04–0.87), as shown in Figure 5. Here, ACE is linked to hydrops fetalis.