Cardiac Intervention Improves Heart Disease and Clinical Outcomes in Patients With Muscular Dystrophy in a Multidisciplinary Care Setting

Abstract

Background Patients with muscular dystrophy (MD) represent a vulnerable patient population with no clearly defined care model in modern-day clinical practice to manage a high burden of heart disease and comorbidities. We demonstrate the effectiveness of cardiac interventions, namely the initiation and optimization of medical and device therapies, as part of a multidisciplinary care approach to improve clinical outcomes in patients with MD. Methods and Results We conducted a prospective cohort study at the Neuromuscular Multidisciplinary clinic following patients with dystrophinopathies, limb-girdle MD, type 1 myotonic dystrophy, and facioscapulohumeral MD. A negative control group classified as non-MD myopathies without heart disease, was also tracked. Our cohort of 185 patients (median age: 42 years; 79 [42.7%] women), included 145 patients with MD. Cardiomyopathy was present in 65.6% of the patients with dystrophinopathies (21 of 32) and 27.3% of the patients with limb-girdle MD (9 of 33). Conduction abnormalities were common in type 1 myotonic dystrophy (33.3% [20/60] patients). Cardiac intervention reversed systolic dysfunction, with left ventricular ejection fraction improving from 43% to 50.0% over a 3-year period. A sustained reduction in healthcare utilization was also observed. The number of outpatient clinic visits decreased from 3.0 to 1.5 visits per year, the duration of hospitalizations was reduced from 14.2 to 0.9 days per year, and the number of cardiac-related hospitalizations decreased from 0.4 to 0.1 hospitalizations per year associated with low mortality. Conclusions Our study demonstrates that cardiac intervention as part of a comprehensive multidisciplinary care approach to treating patients with MD leads to a sustained improvement in clinical outcomes.

Keywords: heart disease; medical therapy; multidisciplinary care; muscular dystrophy; outcome data.

Figure 1

Cardiac assessment of patients with muscular dystrophy (MD) in the Neuromuscular Multidisciplinary (NMMD) clinic. Cardiac assessment and intervention applied through the NMMD clinic care pathway (A). Prevalence of cardiomyopathy in patients with MD (B). Heart failure diagnosed in patients at their initial NMMD clinic visit (C). Arrhythmia burden as captured by ECG, Holter monitoring, and device interrogation (D). DM1 indicates type 1 myotonic dystrophy; FSHD, facioscapulohumeral muscular dystrophy; LGMD, limb‐girdle muscular dystrophy; ND, not detected.

Figure 2

Cardiac assessment and management in a multidisciplinary setting improves outcomes in patients with muscular dystrophy (MD). MRI indicates magnetic resonance imaging; NMMD, Neuromuscular Multidisciplinary.

Figure 3

Uptitration of medical therapy and increase in device implantation following the initial clinic visit in patients with muscular dystrophy (MD). Baseline use of angiotensin‐converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), β‐blockers, mineralocorticoid receptor antagonists (MRAs) (before), and their initiation at the initial Neuromuscular Multidisciplinary clinic visit (after) (A); and their uptitration following the initial visit (B). Implantable cardioverter‐defibrillator (ICD) and pacemaker (including cardiac resynchronization therapy) implantation (C). Maximum tolerated dose (MTD) as defined by 2016 American Heart Association guidelines for the diagnosis and treatment of acute and chronic heart failure.

Figure 4

Improvement in left ventricular ejection fraction (LVEF) in the various muscular dystrophy (MD) cohorts in response to multidisciplinary care. LVEF obtained by cardiac magnetic resonance imaging and/or echocardiogram for 57 patients with cardiomyopathy, with 3 years of imaging data, shown as the median LVEF at the time of their initial clinic visit and at their 3‐year follow‐up. DM1 indicates type 1 myotonic dystrophy; FSHD, facioscapulohumeral muscular dystrophy; LGMD, limb‐girdle muscular dystrophy.

Figure 5

Marked improvement in clinical outcomes in the various muscular dystrophy (MD) cohorts in response to multidisciplinary care. Comparing the rates of unplanned, all‐cause outpatient clinic visits (A), duration of hospitalizations (B), and incidence of cardiac hospitalizations (C) following a 6‐month period of patient assessment and care and within 3 years of the initial Neuromuscular Multidisciplinary clinic visit.