Clinical Scorecard: Assessment of Cardiac Function in Individuals with Muscular Dystrophy

At a Glance

Key Highlights

• VAC (Ea/Ees ratio) is a load-adjusted, dimensionless index reflecting ventricular performance and arterial load interaction.
• Higher VAC values indicate worse cardiac function and reduced ventricular efficiency in MD patients.
• Echocardiographic VAC measurement may enhance risk stratification and therapeutic decision-making beyond standard volume and function metrics.

Guideline-Based Recommendations

Diagnosis

• Routine echocardiographic screening for subclinical cardiac dysfunction in MD patients.
• Use of VAC ratio derived from non-invasive echocardiographic measurements to assess cardiovascular performance.

Management

• Consider ACE inhibitors or angiotensin receptor blockers (ARBs) in patients with MD to manage cardiac dysfunction.
• Monitor ambulatory status and disease phenotype to guide therapeutic decisions.

Monitoring & Follow-up

• Longitudinal echocardiographic assessment including VAC, LV ejection fraction, and elastance parameters.
• Regular blood pressure measurement during echocardiography for accurate VAC calculation.

Risks

• Progression to ventricular dilation and dysfunction despite normal initial echocardiographic parameters.
• Higher VAC ratios correlate with worse disease phenotype and progression.

Patient & Prescribing Data

46 patients with muscular dystrophy (76% Duchene, 24% Becker), median diagnosis age 9.8 years

70% received oral steroids; 65% were on ACE inhibitors or ARBs at initial echocardiogram; mean LVEF was 58% ± 8%

Clinical Best Practices

• Incorporate VAC measurement into routine echocardiographic evaluation of MD patients for early detection of cardiac dysfunction.
• Use standardized echocardiographic protocols following American Society of Echocardiography guidelines.
• Perform longitudinal follow-up with paired echocardiograms to monitor disease progression and treatment response.
• Consider genetic risk factors and ambulatory status when assessing cardiac risk and planning management.

References

• Dilated cardiomyopathy in muscular dystrophy
• Myocardial fibrosis precedes ventricular dysfunction
• Ventriculoarterial coupling and cardiovascular performance
• Echocardiographic assessment guidelines