Increased amount of interstitial fibrosis predicts ventricular arrhythmias, and is associated with reduced myocardial septal function in patients with obstructive hypertrophic cardiomyopathy

Vibeke M Almaas; Kristina H Haugaa; Erik H Strøm; Helge Scott; Christen P Dahl; Trond P Leren; Odd R Geiran; Knut Endresen; Thor Edvardsen; Svend Aakhus; Jan Peder Amlie

doi:10.1093/europace/eut028

Increased amount of interstitial fibrosis predicts ventricular arrhythmias, and is associated with reduced myocardial septal function in patients with obstructive hypertrophic cardiomyopathy

Europace. 2013 Sep;15(9):1319-27. doi: 10.1093/europace/eut028. Epub 2013 Feb 20.

Authors

Vibeke M Almaas¹, Kristina H Haugaa, Erik H Strøm, Helge Scott, Christen P Dahl, Trond P Leren, Odd R Geiran, Knut Endresen, Thor Edvardsen, Svend Aakhus, Jan Peder Amlie

Affiliation

¹ Department of Cardiology, Oslo University Hospital, Rikshospitalet, PO Box 4950, Nydalen, N-0424 Oslo, Norway. vibeke.marie.almaas@ous-hf.no

PMID: 23426552
DOI: 10.1093/europace/eut028

Abstract

Aims: Reduced echocardiographic strain is associated with ventricular arrhythmias in hypertrophic cardiomyopathy (HCM) patients. The aim of this cross-sectional study was to investigate which type of histological fibrosis contributes to ventricular arrhythmias and reduced septal longitudinal strain, in obstructive HCM-patients with or without additional coronary artery disease (CAD) and/or hypertension (HT).

Methods and results: Sixty-three HCM-patients (mean age 57 ± 13 years) were included. Strain by speckle tracking echocardiography was performed prior to either percutaneous transluminal septal ablation (n = 37) or septal myectomy (n = 26). In 24 patients myectomy specimens were available (histology population) and allowed determination of %area of interstitial and replacement fibrosis. Twenty-nine (46%) patients had concomitant CAD and/or HT, and 15 (24%) experienced ventricular arrhythmias defined as documented ventricular tachycardia or arrhythmogenic suspected syncope. The patients with ventricular arrhythmias had lower septal longitudinal strain compared with those without arrhythmias (-9.0 ± 4.0 vs. -13.6 ± 5.6%, P = 0.006). In the histology population reduced septal longitudinal strain correlated to interstitial (R(2) = 0.36 P = 0.003), but not to replacement fibrosis (R(2) = 0.03 P = 0.43). By logistic regression analyses, interstitial fibrosis predicted ventricular arrhythmias (OR 1.16, 95% CI 1.02-1.32, P = 0.03), while replacement fibrosis did not (OR 1.22, 95% CI 0.93-1.59, P = 0.15).

Conclusion: Total amount of fibrosis was a marker of ventricular arrhythmias in obstructive HCM-patients. Interstitial fibrosis seemed to be more important compared with replacement fibrosis in arrhythmogenesis, and was related to reduced septal myocardial function. These findings suggest that interstitial fibrosis may play an important role as the arrhythmogenic substrate, and that strain echocardiography can help detection of patients at risk.

Keywords: Echocardiography; Hypertrophic cardiomyopathy; Myocardial fibrosis; Ventricular arrhythmias.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Cardiomyopathy, Hypertrophic / complications*
Cardiomyopathy, Hypertrophic / diagnostic imaging*
Echocardiography / methods*
Elasticity Imaging Techniques / methods*
Endomyocardial Fibrosis / complications*
Endomyocardial Fibrosis / diagnostic imaging*
Female
Humans
Male
Middle Aged
Reproducibility of Results
Sensitivity and Specificity
Ventricular Fibrillation / complications*
Ventricular Fibrillation / diagnostic imaging*