Daniel P. Fishbein

Prognostic importance of defibrillator shocks in patients with heart failure.

BACKGROUND Patients with heart failure who receive an implantable cardioverter-defibrillator (ICD) for primary prevention (i.e., prevention of a first life-threatening arrhythmic event) may later receive therapeutic shocks from the ICD. Information about long-term prognosis after ICD therapy in such patients is limited. METHODS Of 829 patients with heart failure who were randomly assigned to ICD therapy, we implanted the ICD in 811. ICD shocks that followed the onset of ventricular tachycardia or ventricular fibrillation were considered to be appropriate. All other ICD shocks were considered to be inappropriate. RESULTS Over a median follow-up period of 45.5 months, 269 patients (33.2%) received at least one ICD shock, with 128 patients receiving only appropriate shocks, 87 receiving only inappropriate shocks, and 54 receiving both types of shock. In a Cox proportional-hazards model adjusted for baseline prognostic factors, an appropriate ICD shock, as compared with no appropriate shock, was associated with a significant increase in the subsequent risk of death from all causes (hazard ratio, 5.68; 95% confidence interval [CI], 3.97 to 8.12; P<0.001). An inappropriate ICD shock, as compared with no inappropriate shock, was also associated with a significant increase in the risk of death (hazard ratio, 1.98; 95% CI, 1.29 to 3.05; P=0.002). For patients who survived longer than 24 hours after an appropriate ICD shock, the risk of death remained elevated (hazard ratio, 2.99; 95% CI, 2.04 to 4.37; P<0.001). The most common cause of death among patients who received any ICD shock was progressive heart failure. CONCLUSIONS Among patients with heart failure in whom an ICD is implanted for primary prevention, those who receive shocks for any arrhythmia have a substantially higher risk of death than similar patients who do not receive such shocks.

Maximizing Survival Benefit With Primary Prevention Implantable Cardioverter-Defibrillator Therapy in a Heart Failure Population

Background— Although implantable cardioverter-defibrillator (ICD) therapy reduces mortality in moderately symptomatic heart failure patients with an ejection fraction ≤35%, many such patients do not require ICD shocks over long-term follow-up. Methods and Results— Using a modification of a previously validated risk prediction model based on routine clinical variables, we examined the relationship between baseline predicted mortality risk and the relative and absolute survival benefits of ICD treatment in the primary prevention Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT). In the placebo arm, predicted 4-year mortality grouped into 5 equal-sized risk groups varied from 12% to 50% (c statistic=0.71), whereas the proportion of SCD in those same risk groups decreased from 52% to 24% of all deaths. ICD treatment decreased relative risk of SCD by 88% in the lowest-risk group versus 24% in the highest-risk group (P=0.009 for interaction) and decreased relative risk of total mortality by 54% in the lowest-risk group versus no benefit (2%) in the highest-risk group (P=0.014 for interaction). Absolute 4-year mortality reductions were 6.6%, 8.8%, 10.6%, 14.0%, and −4.9% across risk quintiles. In highest-risk patients (predicted annual mortality >20%), no benefit of ICD treatment was seen. Projected over each patients predicted lifespan, ICD treatment added 6.3, 4.1, 3.0, 1.9, and 0.2 additional years of life in the lowest- to highest-risk groups, respectively. Conclusions— A clinical risk prediction model identified subsets of moderately symptomatic heart failure patients in SCD-HeFT in whom single-lead ICD therapy was of no benefit and other subsets in which benefit was substantial.

Incidence and Clinical Features of Ganciclovir- Resistant Cytomegalovirus Disease in Heart Transplant Recipients

BACKGROUND The incidence and clinical and virologic aspects of ganciclovir-resistant cytomegalovirus (CMV) disease have not been well-characterized in heart transplant recipients. METHODS We retrospectively analyzed all patients who underwent their first heart transplantation during the period from 1 January 1995 through 30 June 2005 at a single health care center. Cox proportional hazard regression was used to assess the relationship between clinical variables and CMV disease. Portions of the UL97 gene were sequenced in patients with slow clinical and/or virologic response to ganciclovir therapy. RESULTS Cytomegalovirus disease developed in 32 (11.7%) of 274 patients at a median of 4.2 months after transplantation (range, 1.8-11.6 months after transplantation) and was independently associated with donor-seropositive/recipient-seronegative (D+/R-) serostatus (adjusted hazard ratio, 6.93; P<.001). The incidence of ganciclovir-resistant CMV disease was 1.5% overall (4 of 274 patients), 5% among D+/R- serostatus recipients (4 of 80 patients), and 12.5% among patients who developed CMV disease (4 of 32 patients). Ganciclovir-resistant CMV disease was significantly associated with D+/R- serostatus (4 [5%] of 80 vs. 0 [0%] of 153 patients; P=.02), greater prior exposure to ganciclovir (median duration of exposure, 150 vs. 69 days; P=.003), and substantial morbidity, including prolonged CMV-associated hospitalization (median duration of hospitalization, 66 vs. 0 days; P<.01). CONCLUSIONS CMV disease, including ganciclovir-resistant disease, is an important clinical problem in D+/R- heart transplant recipients who receive antiviral prophylaxis. Strategies specifically designed to reduce the incidence and impact of CMV disease in this population are warranted.

Predictive value of the Seattle Heart Failure Model in patients undergoing left ventricular assist device placement

BACKGROUND Left ventricular assist devices (LVADs) are increasingly used in advanced heart failure patients. Despite proven efficacy, optimal timing of LVAD implantation is not well defined. METHODS Patients receiving an LVAD were prospectively recorded. Laboratory and clinical data were extracted and used to calculate the predicted survival with medical therapy using the Seattle Heart Failure Model (SHFM). This was compared with observed survival, hospital length of stay and timeliness of discharge. RESULTS We identified 104 patients. Survival with an LVAD vs SHFM predicted survival was 69% vs 11% at 1 year, corresponding to a hazard ratio of 0.17 (p < 0.0001). SHFM-estimated 1-year survival with medical therapy increased from 4% in 1997 to 2004 to 25% in 2007-2008 (p < 0.0001). Subgroup analysis of higher vs lower risk LVAD patients showed observed 1-year survival of 83% vs 57% (p = 0.04). The lower risk group had a shorter length of stay (46 vs 75 days, p = 0.03), along with higher rates of discharge prior to transplant (88% vs 61%, p = 0.01) and discharge within 60 days of LVAD placement (77% vs 52%, p = 0.03). CONCLUSIONS The SHFM allows prediction of important features of a patients hospital course post-operatively, including length of stay and 1-year survival. Given evidence of improved survival and shorter hospital stay in lower risk patients, earlier LVAD placement based on a prediction model like the SHFM should be considered in advanced heart failure patients. The SHFM may have utility as a virtual control arm for single-arm LVAD trials.

Systematic donor selection review process improves cardiac transplant volumes and outcomes

BACKGROUND Heart transplant remains the definitive therapy for advanced heart failure patients but is limited by organ availability. We identified a large number of donor hearts from our organ procurement organization (OPO) being exported to other regions. METHODS We engaged a multidisciplinary team including transplant surgeons, cardiologists, and our OPO colleagues to identify opportunities to improve our center-specific organ utilization rate. We performed a retrospective analysis of donor offers before and after institution of a novel review process. RESULTS Each donor offer made to our program was reviewed on a monthly basis from July 2013 to June 2014 and compared with the previous year. This review process resulted in a transplant utilization rate of 28% for period 1 versus 49% for period 2 (P = .007). Limiting the analysis to offers from our local OPO changed our utilization rate from 46% to 75% (P = .02). Transplant volume increased from 22 to 35 between the 2 study periods. Thirty-day and 1-year mortality were unchanged over the 2 periods. A total of 58 hearts were refused by our center and transplanted at other centers. During period 1, the 30-day and 1-year survival rates for recipients of those organs were 98% and 90%, respectively, comparable with our historical survival data. CONCLUSIONS The simple process of systematically reviewing donor turndown events as a group tended to reduce variability, increase confidence in expanded criteria for donors, and resulted in improved donor organ utilization and transplant volumes.

Right Ventricular Sarcoidosis: Is It Time for Updated Diagnostic Criteria?

A 55-year-old woman with a history of complete heart block, atrial flutter, and progressive right ventricular failure was referred to our tertiary care center to be evaluated for cardiac transplantation. The patients clinical course included worsening right ventricular dysfunction for 3 years before the current evaluation. Our clinical findings raised concerns about arrhythmogenic right ventricular cardiomyopathy. Noninvasive imaging, including a positron emission tomographic scan, did not reveal obvious myocardial pathologic conditions. Given the end-stage nature of the patients right ventricular failure and her dependence on inotropic agents, she underwent urgent listing and subsequent heart transplantation. Pathologic examination of the explanted heart revealed isolated right ventricular sarcoidosis with replacement fibrosis. Biopsy samples of the cardiac allograft 6 months after transplantation showed no recurrence of sarcoidosis. This atypical presentation of isolated cardiac sarcoidosis posed a considerable diagnostic challenge. In addition to discussing the patients case, we review the relevant medical literature and discuss the need for updated differential diagnostic criteria for end-stage right ventricular failure that mimics arrhythmogenic right ventricular cardiomyopathy.

Toward Genetics-Driven Early Intervention in Dilated Cardiomyopathy: Design and Implementation of the DCM Precision Medicine Study

Background— The cause of idiopathic dilated cardiomyopathy (DCM) is unknown by definition, but its familial subtype is considered to have a genetic component. We hypothesize that most idiopathic DCM, whether familial or nonfamilial, has a genetic basis, in which case a genetics-driven approach to identifying at-risk family members for clinical screening and early intervention could reduce morbidity and mortality. Methods— On the basis of this hypothesis, we have launched the National Heart, Lung, and Blood Institute- and National Human Genome Research Institute-funded DCM Precision Medicine Study, which aims to enroll 1300 individuals (600 non-Hispanic African ancestry, 600 non-Hispanic European ancestry, and 100 Hispanic) who meet rigorous clinical criteria for idiopathic DCM along with 2600 of their relatives. Enrolled relatives will undergo clinical cardiovascular screening to identify asymptomatic disease, and all individuals with idiopathic DCM will undergo exome sequencing to identify relevant variants in genes previously implicated in DCM. Results will be returned by genetic counselors 12 to 14 months after enrollment. The data obtained will be used to describe the prevalence of familial DCM among idiopathic DCM cases and the genetic architecture of idiopathic DCM in multiple ethnicity–ancestry groups. We will also conduct a randomized controlled trial to test the effectiveness of Family Heart Talk, an intervention to aid family communication, for improving uptake of preventive screening and surveillance in at-risk first-degree relatives. Conclusions— We anticipate that this study will demonstrate that idiopathic DCM has a genetic basis and guide best practices for a genetics-driven approach to early intervention in at-risk relatives. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT03037632.