The Rhythm | Issue 15
Issue 15 | Week of 13 July 2026
No major cardiology congress fell this week. The evidence arrived through journal publication, and it was thinner than most weeks this year, but a single thread ran through what did appear: cardiology repeatedly asking whether a default setting, a default treatment, or a default assumption of safety actually deserves the confidence placed in it.
Cardiology Intelligence Briefing: second-guessing the default
Cardiology spent this week questioning assumptions that had quietly become routine. The clearest example came from critical care, where the anticoagulation target used during extracorporeal membrane oxygenation had been inherited from an entirely different population and accepted for decades without ever being tested properly in ECMO itself. When it finally was, a lower target performed no worse on the outcomes that mattered. It was not a breakthrough, but it was a reminder that long-standing practice is not the same as evidence.1
The same instinct to re-examine familiar thinking appeared elsewhere. A large registry of patients with apparently mild, asymptomatic hypertrophic cardiomyopathy showed that a reassuring label does not necessarily predict a reassuring future, with around one in five patients experiencing a major cardiovascular event despite their initially low-risk profile.2 Meanwhile, a prespecified analysis of finerenone found no evidence that baseline blood pressure should determine who receives treatment, challenging a common reason for therapeutic hesitation rather than the efficacy of the drug itself.3
The final lesson was that cardiology may already possess more prognostic information than it routinely uses. Among patients supported with durable left ventricular assist devices, the degree of ventricular recovery identified those at substantially different risk of later arrhythmia and cardiovascular events, even without clearly separating survival.4 And a proteomic risk score improved mortality prediction beyond established clinical models and natriuretic peptides, suggesting that future risk stratification may depend less on discovering entirely new diseases than on measuring familiar ones more precisely.5
None of these studies rewrites a guideline on its own. Together, they illustrate something quieter but equally important: progress often comes not from replacing yesterday's practice, but from testing the assumptions that have become embedded within it. The field moved forward this week by becoming a little less certain about what it thought it already knew.
