Israel Medical Association Journal

Background: Hypertrophic cardiomyopathy (HCM) is a familial disease with autosomal dominant inheritance and age-dependent penetrance, caused primarily by mutations of sarcomere genes. Because the clinical variability of HCM is related to its genetic heterogeneity, genetic studies may improve the diagnosis and prognostic evaluation in HCM.

Objectives: To analyze the impact of genetic diagnosis on the clinical management of HCM.

Methods: Genetic studies were performed for either research or clinical reasons. Once the disease-causing mutation was identified, the management plan was reevaluated. Family members were invited to receive genetic counseling and encouraged to be tested for the mutation.

Results: Ten mutations in sarcomere protein genes were identified in 9 probands: 2 novel and 8 previously described. Advanced heart failure or sudden death in a young person prompted the genetic study in 8 of the 9 families. Of 98 relatives available for genotyping, only 53 (54%) agreed to be tested. The compliance was higher in families with sudden death and lower in what appeared to be sporadic HCM or elderly-onset disease. Among the healthy we identified 9 carriers and 19 non-carriers. In 6 individuals the test result resolved an uncertainty about "possible HCM." In several cases the genetic result was also used for family planning and played a role in decisions on cardioverter-defibrillator implantation.

Conclusions: Recurrence of a same mutation in different families created an opportunity to apply the information from the literature for risk stratification of individual patients. We suggest that the clinical context determine the indication for genetic testing and interpretation of the results.

Background: Contemporary therapies improve prognosis and may restore left ventricular (LV) size and function.

Objectives: To examine the prevalence, clinical features and therapies associated with reverse remodeling (RR) in dilated cardiomyopathy (DCM).

Methods: The study group comprised 188 DCM patients who had undergone two echo examinations at least 6 months apart. RR was defined as increased LV ejection fraction (LVEF) by ≥ 10% concomitant with ≥ 10% decreased LV end-diastolic dimension.

Results: RR occurred in 50 patients (26%) and was associated with significantly reduced end-systolic dimension, left atrial size, grade of mitral regurgitation, and pulmonary artery pressure. NYHA class improved in the RR group. RR was less common in familial DCM and a long-standing disease and was more prevalent in patients with prior exposure to chemotherapy. Recent-onset disease, lower initial LVEF and normal electrocardiogram were identified as independent predictors of RR. Beta-blocker dose was related to improved LVEF but not to RR. Over a mean follow-up of 23 months, 16 patients (12%) from the 'no-RR' group died or underwent heart transplantation compared to none from the RR group (P < 0.01).

Conclusions: Contemporary therapies led to an an improvement in the condition of a considerable number of DCM patients. A period of close observation while optimizing medical therapy should be considered before deciding on invasive procedures. 

Objectives: To determine if low plasma vitamin D level is a risk factor for MAEs in statin users.

Methods: Plasma levels of 25(OH) vitamin D were measured as part of the routine evaluation of unselected statin-treated patients attending the coronary and lipid clinics at our hospital during the period 2007–2010. Medical data on muscle complaints and statin use were retrieved from the medical files. Creatine kinase (CK) levels were derived from the hospital laboratory database.

Results: The sample included 272 patients (141 men) aged 33–89 years. Mean vitamin D level was 48.04 nmol/L. Levels were higher in men (51.0 ± 20.5 vs. 44.7 ± 18.9 nmol/L, P = 0.001) and were unaffected by age. MAEs were observed in 106 patients (39%): myalgia in 95 (35%) and CK elevation in 20 (7%); 11 patients (4%) had both. There was no difference in plasma vitamin D levels between patients with and without myalgia (46.3 ± 17.7 vs. 48.9 ± 21.0 nmol/L, P = 0.31), with and without CK elevation (50.2 ± 14.6 vs. 47.8 ± 20.3 nmol/L, P = 0.60), or with or without any MAE (50.4 ± 15.0 vs. 47.8 ± 10.2 nmol/L, P = 0.27). These findings were consistent when analyzed by patient gender and presence/absence of coronary artery disease, and when using a lower vitamin D cutoff (< 25 nmol/L).

Conclusions: There is apparently no relationship between plasma vitamin D level and risk of MAEs in statin users.

Background: Determining the prognosis of patients with heart failure is essential for patient management and clinical trial conduct. The relative value of traditional prognostic criteria remains unclear and the assessment of long-term prognosis for individual patients is problematic.

Objectives: To determine the ability of clinical, hemodynamic and echocardiographic parameters to predict the long-term prognosis of patients with idiopathic dilated cardiomyopathy.

Methods: We investigated the ability of clinical, hemodynamic and echocardiographic parameters to predict the long-term prognosis of individual patients in a large, representative, contemporary cohort of idiopathic dilated cardiomyopathy (IDCM) patients referred to Johns Hopkins from 1997 to 2004 for evaluation of cardiomyopathy. In all patients a baseline history was taken, and physical examination, laboratory studies, echocardiogram, right heart catheterization and endomyocardial biopsy were performed.

Results: In 171 IDCM patients followed for a median 3.5 years, there were 50 long-term event-free survivors (LTS) (median survival 6.4 years) and 34 patients died or underwent ventricular assist device placement or transplantation within 5 years (NLTS; non-long-term survivors) (median time to event 1.83 years. Established risk factors (gender, race, presence of diabetes, serum creatinine, sodium) and the use of accepted heart failure medications (angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta blockers) were similar between the two groups. Although LTS had younger age, higher ejection fraction (EF) and lower New York Heart Association (NYHA) class at presentation, the positive predictive value of an EF< 25% was 64% (95% CI 41%–79%) and of NYHA class > 2 was 53% (95% CI 36–69%). A logistic model incorporating these three variables incorrectly classified 29% of patients.

Conclusions: IDCM exhibits a highly variable natural history and standard clinical predictors have limited ability to classify IDCM patients into broad prognostic categories. These findings suggest that there are important host-environmental factors still unappreciated in the biology of IDCM.
 

Background: Myotonic dystrophy type 2 (DM2) is an autosomal dominant, multisystem disorder caused by a CCTG tetranucleotide repeat expansion located in intron 1 of the zinc finger protein 9 gene (ZNF9 gene) on chromosome 3q 21.3.

Objectives: To describe the clinical, electrophysiologic and pathologic findings in patients with myotonic dystrophy 2.

Methods: We evaluated 10 patients genetically, clinically and electrophysiologically during the years 2007 to 2008.

Results: All patients were of Jewish European ancestry. Among affected individuals, eight patients had symptoms of proximal muscle weakness, two had muscle pain, and two exhibited myotonia. On physical examination six patients had severe weakness of hip flexor muscles. Seven individuals underwent cataract surgery, and cardiac involvement was seen in one case. On the initial electromyographic (EMG) examination five patients demonstrated myotonic discharges; repeated studies showed these discharges in nine cases. Six muscle biopsies showed non-specific pathological changes. Seven patients had an affected first-degree relative with either a diagnosed or an undiagnosed muscular disorder, consistent with an autosomal dominant trait.

Conclusions: DM2 may often present with proximal muscle weakness without myotonia. EMG may initially fail to show myotonic discharges, but these discharges may eventually show in most cases on repeated EMG. Thus, DM2 may be underdiagnosed and should be included in the differential diagnosis of adult patients of Jewish European ancestry presenting with proximal lower limb weakness.