Killip scale reclassification according to lung ultrasound: Killip pLUS

Aims: The Killip scale remains a fundamental tool for prognostic assessment in ST-segment elevation myocardial infarction (STEMI) due to its simplicity and predictive value. Lung ultrasound (LUS) has emerged as a valuable adjunct for diagnosing and predicting outcomes in heart failure (HF) and STEMI patients, even those with subclinical congestion. We created a new classification (Killip pLUS), which reclassifies Killip I and II patients into an intermediate category (Killip I pLUS) based on LUS results. This category included Killip I patients and ≥1 positive zone (≥3 B-lines) and Killip II with 0 positive zones. We aimed to evaluate this new classification by comparing it with the Killip scale and a previous LUS-based reclassification scale (LUCK scale).

Methods and results: Lung ultrasound was performed within 24 h of admission in a multicentre cohort of 373 patients admitted for STEMI. In-hospital mortality and major adverse cardiovascular events within one year after admission, comprising mortality or readmission for HF, acute coronary syndrome, or stroke, were analysed. When predicting in-hospital mortality, the global comparison of these three classifications was statistically significant: Killip pLUS area under the curve (AUC) 0.90 (95% CI 0.85-0.95) vs. Killip AUC 0.85 (95% CI 0.73-0.96) vs. LUCK 0.83 (95% CI 0.70-0.95), P = 0.024. To predict events during follow-up, the comparison between scales was also significant: Killip pLUS 0.77 (95% CI 0.71-0.85) vs. Killip 0.72 (95% CI 0.65-0.79) vs. LUCK 0.73 (95% CI 0.66-0.81), P = 0.033.

Conclusion: The Killip pLUS scale provides enhanced risk stratification compared to the Killip and LUCK scales while preserving simplicity.