Midwall Striae Fibrosis Is Reliable Predictor of HF Admission

Among patients with dilated cardiomyopathy (DCM), midwall striae (MWS) fibrosis was shown to be an independent and powerful predictor of clinical outcomes; in particular, hospitalization for heart failure. The MWS was detected by late gadolinium enhancement (LGE) imaging.

These new prospective, observational study findings on 719 patients come from a team at Stephenson Cardiac Imaging Centre, Libin Cardiovascular Institute of Alberta, and the departments of Diagnostic Imaging and Cardiac Services at University of Calgary. They appear in a recent issue of Scientific Reports, and were found via a subanalysis of the Cardiovascular Imaging Registry of Calgary at the Libin Cardiovascular Institute.

The primary outcome of interest was hospital admission for heart failure, defined by International Classification of Diseases, 10th Revision codes and confirmed by hospitalization within at least 24 hours. Secondary heart failure and arrhythmic composite were secondary end points. Patients were recruited between January 2015 and May 2018 and then followed for at least 1 year.

“MWS fibrosis of the basal septum is observed in approximately one-third of DCM patients referred for LGE-MRI. Across numerous studies this marker has been associated with elevated risk of all-cause death and arrhythmic death or appropriate implantable cardioverter defibrillator (ICD) therapy. However, the value of this unique marker to identify patients at elevated risk of heart failure hospitalization is poorly explored,” authors explained. “We investigated its role to predict heart failure admission and relevant secondary outcomes in a large cohort of DCM patients.”

Among the patients, whose median (interquartile range) age was 57 (47-65) years, close to one-third (32%) were shown to have any degree of fibrosis, 25% to have a MWS fibrosis pattern, 8% a subepicardial pattern, 2% a midwall patchy pattern, and 0.4% a diffuse pattern.

Close to the 3-year mark, 15% of the cohort required hospitalization due to heart failure, while 18% experienced a secondary outcome. Seventy-five percent of the study cohort did not have a MWS phenotype. The most common comorbidity was hyperlipidemia (39%) followed by hypertension (35%) and diabetes (15%).

The secondary heart failure outcome comprised of heart transplantation, left ventricular assist device implantation, or death, and the arrhythmia outcome consisted of appropriate ICD therapy, sudden cardiac death, survived sudden cardiac arrest, or sustained ventricular tachycardia requiring cardioversion.

Higher risks of the primary and secondary outcomes were seen across the board, at a 114% greater risk for hospitalization (HR, 2.14; 95% CI, 1.44-3.16), a 115% greater risk of a secondary heart failure outcome (HR, 2.15; 95% CI, 1.50-3.06), and a 123% greater risk of a secondary arrhythmia outcome (HR, 2.23; 95% CI, 1.23-4.03).

Adjusting for age, sex, body mass index, diabetes, hypertension, New York Heart Association class III/IV disease, left and right ventricular ejection fraction, indexed left ventricular mass, MWS fibrosis, and use of angiotensin-converting enzyme inhibitors and beta-blockers continued showed there was a 65% higher risk of admission for heart failure (HR, 1.65; 95% CI, 1.11-2.47) using MWS fibrosis as an independent predictor, as well as a 1-year event rate of 12% compared with 7% among persons without evidence of MWS fibrosis, the authors noted. Diabetes was also shown to be a strong predictor, leading to a 145% greater risk of heart failure admission (HR, 2.45; 95% CI, 1.59-3.77).

In addition, when considering potential variations between participants with a left ventricular ejection fraction (LVEF) greater than 35% or 35% and below—the median LVEF for this study was 40%—events rates were seen to be similar. However, more patients with MWS vs those without had a reduced LVEF (61% vs 34%) and higher left ventricular volume as a result.

When discussing their findings, the authors noted the need for an expanding availability of advanced phenotypic markers to predict major cardiovascular outcomes among patients with systolic heart failure. The current gold standard is left ventricular function; however, DCM has increasingly been recognized as a heterogeneous disease with a complex physiology, they wrote.

“Accordingly, validation of diagnostic markers with capacity to identify patients at high risk of hospitalization for heart failure delivers expanded opportunity for personalized cardiovascular care strategies,” they concluded. “Future randomized controlled trials aimed at expanded the use of intensive heart failure therapies for DCM populations with intermediate range LVEF and MWS fibrosis are warranted.”

Reference

Purmah Y, Cornhill A, Lei LY, et al. Mid-wall striae fibrosis predicts heart failure admission, composite heart failure events, and life-threatening arrhythmias in dilated cardiomyopathy. Sci Rep. Published online February 2, 2022.doi:10.1038/s41598-022-05790-y