Duchenne muscular dystrophy: survival by cardio-respiratory interventions.

We describe survival in Duchenne dystrophy by invasive and noninvasive ventilation vs. untreated. Patients were untreated prior to 1984 (Group 1), underwent tracheotomy from 1984 until 1991 (Group 2), and were managed by noninvasive mechanical ventilation and cardioprotective medications subsequently (Group 3). Symptoms, vital capacity, and blood gases were monitored for all and spirometry, cough peak flows, carbon dioxide tension, and oximetry for Group 3. Sleep nasal ventilation was initiated for symptomatic hypoventilation. An oximeter and mechanical cough assistance were prescribed for maximum assisted cough peak flow <300 L/m. Patients used continuous noninvasive ventilation and mechanically assisted coughing as needed to maintain pulse oxyhemoglobin saturation ≥95%. Survival was compared by Kaplan-Meier analysis. The 56 of Group 1 died at 18.6±2.9, the 21 Group 2 at 28.1±8.3 years of age with three still alive, and the 88 using noninvasive ventilation had 50% survival to 39.6 years, p<0.001, respectively. We conclude that noninvasive mechanical ventilation and assisted coughing provided by specifically trained physicians and therapists, and cardioprotective medication can result in more favorable outcomes and better survival by comparison with invasive treatment.

Beneficial effects of beta-blockers and angiotensin-converting enzyme inhibitors in Duchenne muscular dystrophy.

BACKGROUND: Patients with Duchenne muscular dystrophy (DMD) often have severe heart failure with a high mortality rate. Most DMD patients with cardiomyopathy became symptomatic in their early to middle teens and usually die of congestive heart failure within 2-3 years from the onset of symptoms. It has been reported that the combination of an angiotensin-converting enzyme (ACE) inhibitor and a beta-blocker has additive benefits in patients with heart failure. The aim of this study was to assess whether the combination of an ACE inhibitor and a beta-blocker is associated with long-term survival of DMD patients with left ventricular (LV) dysfunction. METHODS: We retrospectively analyzed the outcomes of 52 DMD patients who had begun treatment for heart failure with an ACE inhibitor and a beta-blocker at National Yakumo Hospital during the period from 1992 to 2005. All patients used wheelchairs in their daily lives. Patients were classified as symptomatic or asymptomatic at the initiation of treatment with these two drugs. Twelve patients who had already had apparent symptoms due to heart failure were enrolled in a treatment group. Forty patients who had no symptoms with reduced LV ejection fraction (≤ 45% in echocardiography) were enrolled in a prevention group. RESULTS: Five-year and 7-year survival rates of all patients were 93 and 84%, respectively. In the treatment group, 5-year and 7-year survival rate were 81 and 71%, respectively. Survival rate became zero at 10.9 years. In the prevention group, 5-year and 7-year survival rates were 97 and 84%, respectively, and 10-year survival rate was 72%. Nine patients in the prevention group remained event-free over 10 years. CONCLUSIONS: In this study, the combination of an ACE inhibitor and a beta-blocker had a beneficial effect on long-term survival of DMD patients with heart failure. The treatment was particularly effective for asymptomatic patients with LV dysfunction.

Myocardial strain changes in Duchenne muscular dystrophy without overt cardiomyopathy.

BACKGROUND: Patients with Duchenne muscular dystrophy (DMD) are at risk of the development of dilated cardiomyopathy and heart failure, thus making early identification of high-risk patients necessary. Myocardial strain imaging (MSI) can be used for quantitative analysis of wall motion of the left ventricle (LV). The aim of this study was to determine whether MSI could detect early changes in myocardial properties in presymptomatic DMD patients with normal LV function. METHODS AND RESULTS: Two-dimensional echocardiographic and tissue Doppler examinations were performed in 13 DMD patients (age range, 11 to 20 years) with normal LV function and in 10 healthy controls. MSI was obtained from tissue Doppler information. In control subjects, strain values in both inner and outer layers of the myocardium were positive at the short-axis image showing the radial systolic thickening. In 10 of the 13 DMD patients, however, myocardial strain showed a negative strain value in systole in the outer layer of the posterolateral wall at the parasternal short-axis image for each cardiac cycle. In 5 of these 10 patients, the timing of the peak systolic velocity at the inferoposterior wall was delayed more than 60 ms than that at the posterolateral wall (mean 80.0+/-17.5 ms). CONCLUSIONS: In some DMD patients with normal LV function, myocardial strain profiles at the posterolateral wall of the LV were different from those in healthy controls, suggesting abnormal myocardial contraction. MSI appears to detect early changes in myocardial features in DMD patients before the onset of overt cardiomyopathy.

Clinical and angiographic outcomes after multi-link PENTA stent implantation in Japanese patients with coronary artery disease.

The flexibility of the Multi-Link (ML) PENTA stent with platform 0.09 to 0.12-mm-thick struts and 12% to 16% metal/artery coverage was improved to facilitate safe delivery in complex coronary lesions. The present study was designed to evaluate the clinical (9-month) and angiographic (6-month) results of the ML PENTA stent in complex coronary lesions (modified American College of Cardiology/American Heart Association lesion type B2 or C) and to determine independent factors correlated with target lesion revascularization. The study population consisted of 86 consecutive patients who had undergone successful coronary ML PENTA stent implantation for coronary artery disease from May 2003 to July 2004 in our hospital. During the follow-up period, cardiac events were documented in 21 (24.4%) of the 86 patients. Target lesion revascularization was required in 16 (18.6%) of the 86 patients. Single logistic regression analysis showed that target lesion revascularization was significantly correlated with lesion length > 2.0 cm, residual percent diameter stenosis after the procedure > 20%, and multiple stents. Multiple logistic regression analysis showed that residual percent diameter stenosis after procedure > 20% (P = 0.0125, odds ratio = 11.585) was the significant explanatory factor of target lesion revascularization. The results of the present study suggest that 9-month clinical and 6-month angiographic outcomes in patients with coronary artery disease treated using the ML PENTA stent were excellent and target lesion revascularization after coronary ML PENTA stent implantation was influenced by residual percent diameter stenosis after the procedure.

Prognostic implications of an initial loss of cardiac metaiodobenzylguanidine uptake and diabetes mellitus in patients with left ventricular dysfunction.

BACKGROUND: Although altered cardiac sympathetic innervation is related to fatal outcome, the mechanisms and prognostic value of an initial cardiac metaiodobenzylguanidine (MIBG) defect are not known. METHODS AND RESULTS: After quantitative cardiac MIBG imaging, 205 patients with left ventricular ejection fraction <50% were prospectively followed up with a primary end-point of cardiac death for 35 months. In regard to 38 cardiac deaths, consisting of 25 pump failure deaths, 11 sudden deaths, and 2 fatal acute myocardial infarctions, multivariate analysis identified diabetes mellitus as a significant independent predictor as well as reduced cardiac MIBG activity, use of nitrate, and New York Heart Association functional status. Independent of washout kinetics and cardiac function, patients with profound loss of initial MIBG uptake and those with late-phase MIBG activity of 1.74 or less had significantly greater mortality rates than did their counterparts. Initial cardiac MIBG activity closely correlated inversely with annual cardiac death rate. CONCLUSIONS: An initial cardiac MIBG defect and presence of diabetes mellitus indicate a low probability of long-term survival. The profound loss of initial MIBG activity is likely to be due to structural deficit of sympathetic neurons themselves, rather than accelerated sympathetic function, suggesting that denervation is one of mechanisms of cardiac sympathetic dysfunction leading to lethal clinical outcomes.