Tag: CMR

Concentric left ventricular hypertrophy rarely leads to dilated cardiomyopathy

Contributor: Jennifer Huang

 

Does concentric left ventricular hypertrophy (LVH) progress to dilated cardiomyopathy (DCM)? It may not be as common as we previously thought and the transition may occur over decades.

1,386 participants of the Dallas Heart Study without baseline LV dilation were included. Ten percent of the participants had baseline LVH (7.2 g/mL0.67  for men and 5.8 g/mL0.67 for women). The study population had a mean age of 44 years, 57% women and 43% black patients. Of note, patients that developed cardiovascular disease during the study period (MI, CABG, PCI, stroke or HF) were not included in the final cohort of 1282. Baseline and follow up cardiac magnetic resonance imaging was performed a median of 7 years after baseline imaging.

An increase in LVEDV was significantly (p<0.01) more common among patients with baseline LVH. However, the change in LVEDV was small (1ml in those with LVH and -2ml in those without) over the 7 year period. Overall, the progression to DCM was 3% in those with LVH and 2% in those without LVH.

In a heartbeat…

LVH hearts tend to slightly increase LVEDV over time, but progression to DCM remains a rare phenomenon, at least in the Dallas Heart Study cohort.

Study Link

MRI findings more prognostic than laboratory values in myocarditis

Contributor: Steven Stroud

 

A cardiac MRI (CMR) is worth a thousand labs. Or, that appears to be the case in myocarditis. Dr. Heidecker et al demonstrated that late gadolinium enhancement (LGE) on CMR is unrelated to cardiac enzymes and inflammatory markers, and more prognostic in myocarditis.

Twenty-four patients were prospectively enrolled (75% male, median age 32, 13% w/ concomitant CAD) at the University of Zurich after being diagnosed with myocarditis. Myocarditis diagnosis was based on clinical features, symptom onset < 10 days, ECG, and elevated high-sensitivity troponin T in the absence of acute obstructive coronary disease.

CMR, high-sensitivity troponin T, creatine kinase (CK), myoglobin, NT-proBNP, and C-Reactive Protein were obtained at presentation and at 3 months follow-up. At 3 months, patients also underwent 48 hour holter monitoring, exercise testing (21/24 patients), and repeat ECG. The patients were monitored for adverse cardiac events (arrhythmias, severe chest pain, or dyspnea) for up to 6 months.

LGE extent (measured as a percentage of LV volume) decreased greater than 20% in 12 (50%), completely resolved in 4 (17%), did not change in 3 (12.5%), and increased greater than 20% in 5 (21%).

Of the 5 patients with an increase in LGE extent, one experienced polymorphic ventricular tachycardia requiring ICD placement. This compares to a larger study that demonstrated 17% of myocarditis patients with LGE at diagnosis experienced an SCD event.

Only CK and myoglobin were related to LGE extent at 3 months, but did not reach statistical significance (P=0.06). Among 21 (88%) patients with normalized serum markers at 3 months, 7 (39%) had resolution of LGE. Male patients were more likely to have a reduction in LGE at 3 month follow-up.

No study is perfect. The limitations include: small, single-center sample size, no patients with prior ICD implantation due to MRI constraints (increasing mean LVEF of included patients), relatively short follow-up period (6 months), and no confirmatory endomyocardial biopsy.

In a heartbeat…

In myocarditis patients with persistent or worsening LGE on CMR may predict arrhythmia better than lab values.

Study Link