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Published on: July 20, 2022
Clinical phenotypes of severe atrial cardiomyopathy and their outcome: A cluster analysis
R Ilieva1, P Kalaydzhiev1, B Slavchev2
1Cardiology Clinic, University Hospital "Tsaritsa Yoanna- USUL" Sofia, Department of Emergency Medicine, Medical University Sofia, Bulgaria.
Insights
This study identified four distinct patient groups within severe atrial cardiomyopathy (AtCM), revealing varied mortality risks associated with specific comorbidities. Understanding these phenotypes is crucial for predicting outcomes in AtCM patients.
Area of Science:
- Cardiology
- Internal Medicine
- Clinical Research
Background:
- Atrial cardiomyopathy (AtCM) presents diverse patient demographics and comorbidities.
- Identifying distinct AtCM phenotypes is essential for understanding disease progression and patient outcomes.
Purpose of the Study:
- To identify phenotype groups within severe AtCM with similar clinical characteristics.
- To compare mortality and atrial fibrillation (AF) event rates among these identified groups.
- To assess predictors of mortality in patients with severe AtCM.
Main Methods:
- Hierarchical cluster analysis using Ward's Method on 11 clinical variables.
- Inclusion criteria: 724 patients with dilated left atrium (LA); 196 met severe AtCM criteria (LA volume index ≥ 50 ml/m²).
- Four clusters were identified based on age, BMI, comorbidities, and AF type.
Main Results:
- Cluster 2 (older, HF, low BMI) exhibited the highest mortality (29.1%).
- Cluster 1 (younger, overweight, paroxysmal AF) showed the highest AF event incidence (37%).
- Heart failure, cancer, and severe tricuspid regurgitation were significant predictors of mortality.
Conclusions:
- Four distinct patient clusters were identified in severe AtCM, each with unique comorbidities and mortality rates.
- While AF event rates were similar across clusters, mortality varied significantly.
- Clinical factors like heart failure and severe tricuspid regurgitation are critical predictors of poor outcomes in AtCM.
Background:
Atrial cardiomyopathy (AtCM) encompasses patients with diverse demographics and comorbidities. This study aimed to identify phenotype groups with similar clinical characteristics, compare their mortality and atrial fibrillation (AF) event rates, and assess predictors of mortality.
Methods And Results:
We performed a hierarchical cluster analysis using Ward's Method, based on 11 clinical variables. Among 724 consecutive patients with a dilated left atrium (LA), only 196 met the criterion for severe AtCM- defined as a dilated LA with a volume index ≥ 50 ml/m2. We identified 4 clusters: Cluster 1 -younger overweight patients with paroxysmal AF; Cluster 2 -older patients with heart failure (HF) and low BMI; Cluster 3 - diabetic patients with HF; and Cluster 4 - older patients with tachycardia-bradycardia syndrome and implanted pacemakers. Over a median follow-up of 20.6 months, Cluster 2 had the highest mortality rate (29.1 %), followed by Cluster 3 (20.6 %), compared to Clusters 1 and 4 (11.4 % and 10.8 %, respectively, p = 0.045). For AF events, Cluster 1 had the highest incidence (37 %), followed by Cluster 3 (35 %), Cluster 2 (24 %), and Cluster 4 (19 %, p = 0.309). Heart failure (HR 4.4, CI 1.5-12.7, p = 0.006), cancer (HR 3.3, CI 1.6-6.9, p = 0.002), and severe tricuspid regurgitation (HR 5.4, CI 2.6-11.3, p < 0.001) were predictors of poor outcomes.
Conclusion:
In severe AtCM patients, four clusters were identified, each with unique comorbidities and mortality rates but similar AF event rates. Clinical and echocardiographic factors were linked to higher mortality risk.
