Phenotypic clustering of patients hospitalized in intensive cardiac care units: Insights from the ADDICT-ICCU study.

BACKGROUND: Intensive cardiac care units (ICCUs) were created to manage ventricular arrhythmias after acute coronary syndromes, but have diversified to include a more heterogeneous population, the characteristics of which are not well depicted by conventional methods. AIMS: To identify ICCU patient subgroups by phenotypic unsupervised clustering integrating clinical, biological, and echocardiographic data to reveal pathophysiological differences. METHODS: During 7-22 April 2021, we recruited all consecutive patients admitted to ICCUs in 39 centers. The primary outcome was in-hospital major adverse events (MAEs; death, resuscitated cardiac arrest or cardiogenic shock). A cluster analysis was performed using a Kamila algorithm. RESULTS: Of 1499 patients admitted to the ICCU (69.6% male, mean age 63.3±14.9 years), 67 (4.5%) experienced MAEs. Four phenogroups were identified: PG1 (n=535), typically patients with non-ST-segment elevation myocardial infarction; PG2 (n=444), younger smokers with ST-segment elevation myocardial infarction; PG3 (n=273), elderly patients with heart failure with preserved ejection fraction and conduction disturbances; PG4 (n=247), patients with acute heart failure with reduced ejection fraction. Compared to PG1, multivariable analysis revealed a higher risk of MAEs in PG2 (odds ratio [OR] 3.13, 95% confidence interval [CI] 1.16-10.0) and PG3 (OR 3.16, 95% CI 1.02-10.8), with the highest risk in PG4 (OR 20.5, 95% CI 8.7-60.8) (all P<0.05). CONCLUSIONS: Cluster analysis of clinical, biological, and echocardiographic variables identified four phenogroups of patients admitted to the ICCU that were associated with distinct prognostic profiles. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT05063097.

Profile of patients hospitalized in intensive cardiac care units in France: ADDICT-ICCU registry.

BACKGROUND: Intensive cardiac care units (ICCU) were initially developed to monitor ventricular arrhythmias after myocardial infarction. In recent decades, ICCU have diversified their activities. AIM: To determine the type of patients hospitalized in ICCU in France. METHODS: We analysed the characteristics of patients enrolled in the ADDICT-ICCU registry (NCT05063097), a prospective study of consecutive patients admitted to ICCU in 39 centres throughout France from 7th-22nd April 2021. In-hospital major adverse events (MAE) (death, resuscitated cardiac arrest and cardiogenic shock) were recorded. RESULTS: Among 1499 patients (median age 65 [interquartile range 54-74] years, 69.6% male, 21.7% diabetes mellitus, 64.7% current or previous smokers), 34.9% had a history of coronary artery disease, 11.7% atrial fibrillation and 5.2% cardiomyopathy. The most frequent reason for admission to ICCU was acute coronary syndromes (ACS; 51.5%), acute heart failure (AHF; 14.1%) and unexplained chest pain (6.8%). An invasive procedure was performed in 36.2%. "Advanced" ICCU therapies were required for 19.9% of patients (intravenous diuretics 18.4%, non-invasive ventilation 6.1%, inotropic drugs 2.3%). No invasive procedures or advanced therapies were required in 44.1%. Cardiac computed tomography or magnetic resonance imaging was carried out in 12.3% of patients. The median length of ICCU hospitalization was 2.0 (interquartile range 1.0-4.0) days. The mean rate of MAE was 4.5%, and was highest in patients with AHF (10.4%). CONCLUSIONS: ACS remains the main cause of admissions to ICCU, with most having a low rate of in-hospital MAE. Most patients experience a brief stay in ICCU before being discharged home. AHF is associated with highest death rate and with higher resource consumption.