Unsupervised clustering of intra-ventricular haemodynamic forces for the phenotyping of left ventricular function in

Lorenzo Airale1,2, Alessandro Giustiniani2,3, Eduard Ródenas-Alesina2,4,5

  • 1Division of Internal Medicine, Hypertension Unit, Department of Medical Sciences, Città della Salute e della Scienza Hospital, University of Turin, Turin, Italy.

Insights

Unsupervised clustering of cardiac haemodynamic forces (HDFs) in non-ischaemic LV cardiomyopathy identifies distinct patient groups. These clusters stratify cardiovascular risk beyond traditional measures like LGE and EF.

Area of Science:

  • Cardiology
  • Biomedical Engineering
  • Medical Imaging

Background:

  • Cardiac magnetic resonance (CMR) is crucial for diagnosing cardiomyopathy.
  • Haemodynamic forces (HDFs) analysis from cine CMR images offers novel insights into heart-blood energy exchange.
  • Previous studies focused on peak HDF values, necessitating exploration of dynamic HDF patterns.

Purpose of the Study:

  • To investigate if unsupervised clustering of HDF curves can identify distinct phenotypes in non-ischaemic LV cardiomyopathy (NILVC).
  • To determine if these identified clusters can stratify cardiovascular (CV) risk in NILVC patients.
  • To assess the prognostic value of HDF patterns beyond established markers.

Main Methods:

  • Retrospective analysis of 279 NILVC patients undergoing CMR.
  • Unsupervised clustering of longitudinal and transversal HDF curves using dynamic time warping and partitioning around medoids.
  • Composite outcome definition: CV mortality, heart failure hospitalization, and ventricular arrhythmias.

Main Results:

  • Three distinct HDF clusters were identified, correlating with worsening left atrial and left ventricular function.
  • A stepwise increase in CV risk profile was observed across the clusters.
  • Clusters 2 and 3 showed significantly higher risk of adverse CV events compared to Cluster 1, even after adjusting for LGE and LV ejection fraction.

Conclusions:

  • Analysis of longitudinal and transversal HDFs throughout the cardiac cycle reveals distinct patient phenotypes in NILVC.
  • These HDF-derived phenotypes possess prognostic value exceeding that of ejection fraction and late gadolinium enhancement.
  • Unsupervised clustering of HDFs offers a promising tool for CV risk stratification in NILVC.
Abstract