Darshak H. Karia

Wearable defibrillator use in heart failure (WIF): results of a prospective registry

BackgroundHeart failure (HF) patients have a high risk of death, and implantable cardioverter defibrillators (ICDs) are effective in preventing sudden cardiac death (SCD). However, a certain percentage of patients may not be immediate candidates for ICDs, particularly those having a short duration of risk or an uncertain amount of risk. This includes the newly diagnosed patients, as well as those on the cardiac transplant list or NYHA class IV heart failure patients who do not already have an ICD. In these patients, a wearable cardioverter defibrillator (WCD) may be used until long term risk of SCD is defined. The purpose of this study was to determine the incidence of SCD in this population, and the efficacy of early defibrillation by a WCD.MethodsTen enrolling centers identified 89 eligible HF patients who were either listed for cardiac transplantation, diagnosed with dilated cardiomyopathy, or receiving inotropic medications. Data collected included medical history, device records, and outcomes (including 90 day mortality).ResultsOut of 89 patients, final data on 82 patients has been collected. Patients wore the device for 75±58 days. Mean age was 56.8±13.2, and 72% were male. Most patients (98.8%) were diagnosed with dilated cardiomyopathy with a low ejection fraction (<40%) and twelve were listed for cardiac transplantation. Four patients were on inotropes. There were no sudden cardiac arrests or deaths during the study. Interestingly, 41.5% of patients were much improved after WCD use, while 34.1% went on to receive an ICD.ConclusionsIn conclusion, the WCD monitored HF patients until further assessment of risk. The leading reasons for end of WCD use were improvement in left ventricular ejection fraction (LVEF) or ICD implantation if there was no significant improvement in LVEF.

Safety and Efficacy of Extracorporeal Shock Wave Myocardial Revascularization Therapy for Refractory Angina Pectoris

OBJECTIVE To assess the safety and efficacy of extracorporeal shockwave myocardial revascularization (ESMR) therapy in treating patients with refractory angina pectoris. PATIENTS AND METHODS A single-arm multicenter prospective trial to assess safety and efficacy of the ESMR therapy in patients with refractory angina (class III/IV angina) was performed. Screening exercise treadmill tests and pharmacological single-photon emission computed tomography (SPECT) were performed for all patients to assess exercise capacity and ischemic burden. Patients were treated with 9 sessions of ESMR to ischemic areas over 9 weeks. Efficacy end points were exercise capacity by using treadmill test as well as ischemic burden on pharmacological SPECT at 4 months after the last ESMR treatment. Safety measures included electrocardiography, echocardiography, troponin, creatine kinase, and brain natriuretic peptide testing, and pain questionnaires. RESULTS Fifteen patients with medically refractory angina and no revascularization options were enrolled. There was a statistically significant mean increase of 122.3±156.9 seconds (38% increase compared with baseline; P=.01) in exercise treadmill time from baseline (319.8±157.2 seconds) to last follow-up after the ESMR treatment (422.1±183.3 seconds). There was no improvement in the summed stress perfusion scores after pharmacologically induced stress SPECT at 4 months after the last ESMR treatment in comparison to that at screening; however, SPECT summed stress score revealed that untreated areas had greater progression in ischemic burden vs treated areas (3.69±6.2 vs 0.31±4.5; P=.03). There was no significant change in the mean summed echo score from baseline to posttreatment (0.4±5.1; P=.70). The ESMR therapy was performed safely without any adverse events in electrocardiography, echocardiography, troponins, creatine kinase, or brain natriuretic peptide. Pain during the ESMR treatment was minimal (a score of 0.5±1.2 to 1.1±1.2 out of 10). CONCLUSION In this multicenter feasibility study, ESMR seems to be a safe and efficacious treatment for patients with refractory angina pectoris. However, larger sham-controlled trials will be required to confirm these findings.

Conivaptan: promise of treatment in heart failure

Conivaptan, the first vasopressin receptor antagonist approved by the FDA, is available for the treatment of hyponatremia in euvolemic and hypervolemic patients. The renin-angiotensin-aldosterone system is activated in heart failure (HF) causing clinical worsening. Arginine vasopressin levels are also elevated in HF. Conivaptan is an effective and FDA approved for the treatment of euvolemic and hypervolemic hyponatremia and may offer an extra treatment option in HF by targeting V1a and V2 receptors. In this article we review the physiology, preclinical studies as well as the human clinical studies on the use of conivaptan and its potential and promise in the treatment of HF.

70 Diagnostic value of serum B-type natriuretic peptide in the diagnosis of congestive heart failure in patients with impaired renal function - do we need a higher cutoff?

regression, and t student test were performed. Results: LogBNP was useful in distinguishing patients with CHF from patients without CHF (AUC=73%, 95%CI, 60% to 87%, p<0.001) in patients with eGFR between 30-90 ml/min/1.73m 2 ; mean BNP was 1143pg/ml in the CHF group vs. 531pg/ml in no CHF (p=0.003). However, logBNP could not distinguish CHF patients from patients without CHF in the group with eGFR between 15-29 ml/min/1.73m 2 (AUC=52%, 95%CI, 6% to 98%, p=0.68). Conclusions: In patients with mild to moderate renal dysfunction, serum BNP may still provide useful diagnostic information if the cutoff is higher (500 pg/ml). In patients with severe renal dysfunction (eGFR <15), BNP is not able to differentiate patients with congestion.