Prognostic Value of the 6-Min Walk Test After Open-Heart Valve Surgery: EXPERIENCE OF A CARDIOVASCULAR REHABILITATION PROGRAM.

PURPOSE: This single-center retrospective analysis aimed to evaluate the prognostic relevance of 6-min walk test (6MWT) in patients admitted to an in-hospital cardiovascular rehabilitation program after open-heart valve surgery. METHODS: One hundred one patients able to perform a 6MWT within the first week of admission (time after surgery: 16 ± 8 d) were included (age 68 ± 11 y; 55% female; median left ventricular ejection fraction 55% [interquartile range: 50-60]; 51% after aortic valve surgery). Study endpoints were cardiovascular death and the combined outcome of cardiovascular death/cardiac hospitalization. Univariate and multivariate analyses were performed to analyze predictive value of the 6MWT. RESULTS: After a median follow-up of 27 mo, cardiovascular mortality was 9.9% while combined endpoint occurrence was 33%. Patients experiencing study endpoints had lower left ventricular ejection fraction, higher N-terminal prohormone of brain natriuretic peptide serum levels, and longer in-hospital stay (all P < .05). The 6MWT distance was a significant predictor of cardiovascular death (hazard ratio [HR] = 0.89, 95% CI: 0.81-0.97, P = .007) and cardiac hospitalizations (HR = 0.95, 95% CI: 0.90-0.99, P = .02). Even after adjusting for the relevant confounding variables of cardiovascular death and cardiac hospitalization, the adjusted HR = 0.88, 95% CI: 0.75-0.98, P = .028 and adjusted HR = 0.95, 95% CI: 0.90-0.99, P = .05, respectively. CONCLUSIONS: In patients admitted to an in-hospital cardiovascular rehabilitation program after open-heart valve surgery, 6MWT proved to be an independent prognostic tool, potentially allowing identification of high-risk patients for whom a more intensive and tailored in-hospital cardiovascular rehabilitation program should be designed and implemented in order to avoid unfavorable cardiovascular events.

Nemaline myopathy and heart failure: role of ivabradine; a case report.

BACKGROUND: Nemaline myopathy (NM) is a rare congenital myopathy characterized by muscle weakness, hypotonia and the presence in muscle fibers of inclusions known as nemaline bodies and a wide spectrum of clinical phenotypes, ranging from severe forms with neonatal onset to asymptomatic forms. The adult-onset form is heterogeneous in terms of clinical presentation and disease progression. Cardiac involvement occurs in the minority of cases and little is known about medical management in this subgroup of NM patients. We report a rare case of heart failure (HF) in a patient with adult-onset NM in whom ivabradine proved to be able to dramatically improve the clinical picture. CASE PRESENTATION: We report a case of a 37-year-old man with adult-onset NM, presenting with weakness and hypotonia of the proximal limb muscles and shoulder girdle, severely limiting daily activities. He developed progressive HF over a period of 6 months while attending a rehabilitation program, with reduced left ventricular ejection fraction (LVEF = 20%), manifested by dyspnea and signs of systemic congestion. The patient was started HF therapy with enalapril, carvedilol, spironolactone and loop diuretics. Target HF doses of these drugs (including carvedilol) were not reached because of symptomatic hypotension causing a high resting heart rate (HR) ≥70 beats per minute (bpm). Further deterioration of the clinical picture occurred with several life-threatening arrhythmic episodes requiring external defibrillation. An implantable cardioverter defibrillator (ICD) was then implanted. Persistent high resting HR was successfully treated with ivabradine with HR lowering from 90 bpm to 55 bpm at 1 month follow up, LVEF rising to 50% at 3 month follow up and to 54% at 2,5 year follow up. To date no more hospitalizations for heart failure occurred. A single hospitalization due to aspiration pneumonia required insertion of a tracheostomy tube to protect airways from further aspiration. At present, the patient is attending a regular rehabilitation program with net improvement in neuromotor control and less limitations in daily activities. CONCLUSIONS: HF is a rare feature of NM, but it can negatively influence prognosis. Conventional HF therapy and/or heart transplant are the only reasonable strategy in these patients. Ivabradine is a useful, effective and safe drug for therapy in NM patients with HF and should be considered when resting HR remains high despite beta-blockers' full titration or beta-blockers' underdosing due to intolerance or side effects.