Association of fibrosis with mortality and sudden cardiac death in patients with nonischemic dilated cardiomyopathy

Area of Science:

• Cardiology
• Cardiovascular Imaging
• Cardiac MRI

Background:

• Risk stratification in nonischemic dilated cardiomyopathy typically relies on left ventricular ejection fraction (LVEF).
• Identifying superior prognostic factors is crucial for optimizing patient selection for interventions like implantable cardioverter-defibrillators (ICDs).

Purpose of the Study:

• To evaluate whether myocardial fibrosis, detected by late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR) imaging, serves as an independent and incremental predictor of mortality and sudden cardiac death (SCD) in dilated cardiomyopathy patients.

Main Methods:

• A prospective, longitudinal study involving 472 patients with dilated cardiomyopathy.
• Cardiovascular magnetic resonance (CMR) imaging was used to determine the presence and extent of midwall replacement fibrosis.
• Patients were followed up for mortality and cardiac events over a median of 5.3 years.

Main Results:

• The presence and extent of midwall fibrosis were independently and incrementally associated with all-cause mortality, cardiovascular mortality, SCD, and heart failure composite endpoints, even after adjusting for LVEF.
• Patients with fibrosis had a significantly higher risk of all-cause mortality (HR, 2.43) and SCD (HR, 4.61).
• Incorporating LGE-CMR findings into risk models significantly improved risk reclassification for mortality and SCD compared to LVEF alone.

Conclusions:

• Late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR) imaging provides independent prognostic information beyond LVEF in nonischemic dilated cardiomyopathy.
• LGE-CMR has the potential to enhance risk stratification for patients with dilated cardiomyopathy.
• Further investigation into the clinical utility of LGE-CMR for risk stratification is warranted.