Sanjeev P. Bhavnani

Therapeutic hypothermia is associated with improved neurologic outcome and survival in cardiac arrest survivors of non-shockable rhythms

BACKGROUND Therapeutic hypothermia improves neurologic outcomes in patients resuscitated from cardiac arrest due to ventricular fibrillation. However, its role in patients with cardiac arrest due to non-shockable rhythms (pulseless electrical activity (PEA) and asystole) is unclear. We hypothesized that therapeutic hypothermia favorably impacts neurologic outcome and survival in patients resuscitated from cardiac arrest due to non-shockable rhythms. METHODS Retrospectively collected data on consecutive adult patients admitted to Hartford Hospital from 1/1/2004 to 11/1/2010 who survived a cardiac arrest due to PEA or asystole were analyzed. Patients who underwent therapeutic hypothermia (1/1/2007-11/1/2010) formed the hypothermia group while patients admitted prior to the institution of therapeutic hypothermia (1/1/2004-1/1/2007) at Hartford Hospital formed the control group. The primary end-point was measured using the Pittsburgh cerebral performance category (CPC) scale and patients were assessed for a good (CPC 1 and 2) or poor (CPC 3-5) neurological outcome prior to discharge from hospital. A secondary end-point was measured as survival at discharge from hospital. RESULTS Of 100 post-cardiac arrest patients included in the study, 15/52 (29%) patients in the hypothermia group had a good neurologic outcome as compared to 5/43 (10%) patients in the control group (P=0.021). On multivariate analysis, the odds ratio for good neurologic outcome and survival at discharge from the hospital with therapeutic hypothermia as compared to control were 4.35 (95% CI 1.10-17.24, P=0.04) and 5.65 (CI 1.66-19.23, P=0.006) respectively. CONCLUSION Therapeutic hypothermia is associated with favorable neurologic outcome and survival in patients resuscitated after cardiac arrest due to non-shockable rhythms.

The prognostic impact of shocks for clinical and induced arrhythmias on morbidity and mortality among patients with implantable cardioverter-defibrillators

BACKGROUND Recent investigations have demonstrated that the occurrence of implantable cardioverter-defibrillator (ICD) shocks is associated with adverse long-term outcomes. These studies have emphasized that the risk is most reasonably due to arrhythmias rather than to the shock itself. We sought to compare the impact of shock delivery for induced ventricular arrhythmias during implantation defibrillation threshold testing and noninvasive electrophysiology study (NIPS) to clinical shocks on long-term outcomes among patients with ICDs. METHODS This was a cohort evaluation of 1,372 patients undergoing ICD implantation at a tertiary hospital from December 1997 to January 2007. The probability of all-cause mortality and hospitalization for acute decompensated heart failure (ADHF) was evaluated based upon the type of ICD shock received using multivariable Cox proportional analyses. The four shock types analyzed were implantation shocks only (n = 694), additional NIPS shocks only (n = 319), additional appropriate shocks only (n = 128), or additional inappropriate shocks only (n = 104). RESULTS The risk of death (adjusted hazard ratio [AHR] 0.91 [95% confidence interval (CI) 0.69-1.20]; P = .491) or ADHF (AHR 0.71 [95% CI 0.46-1.16]; P = .277) were similar between recipients of NIPS shocks and recipients of implantation shocks. Receiving an appropriate ICD shock increased the risk of death (AHR 2.09 [95% CI 1.38-2.69]; P <.001) and ADHF (AHR 2.40 [95% CI 1.51-3.81]; P <.002) as compared with implantation shocks and also increased the risk of death (AHR 2.61 [95% CI 1.86-3.67]; P <.001) and ADHF (AHR 2.29 [95% CI 1.33-3.97]; P = .003) as compared with NIPS shocks. CONCLUSIONS ICD shocks delivered during induced ventricular arrhythmias at the time of NIPS testing does not increase the risk of death or ADHF as compared with recipients of appropriate ICD shocks. The occurrence of spontaneous arrhythmias in vulnerable substrates may explain the increased risk.

Association between statin therapy and reductions in atrial fibrillation or flutter and inappropriate shock therapy.

AIMS In patients without implantable cardioverter defibrillators (ICDs), statins have been shown to reduce the incidence of atrial fibrillation and atrial flutter (AF/AFL). We sought to determine if statin therapy could reduce the occurrence of AF/AFL with rapid ventricular rates with and without inappropriate shock therapy among a large heterogeneous ICD cohort. METHODS AND RESULTS We prospectively followed 1445 consecutive patients receiving an ICD for the primary (n = 833) or secondary (n = 612) prevention from December 1997 through January 2007. Outcome measures include incidence of AF/AFL that initiated ICD therapy or was detected during ICD interrogation. Cox hazard regression analyses were conducted to determine the predictors of AF/AFL with and without inappropriate shock delivery and did not include inappropriate shocks resulting from lead dysfunction or other exogenous factors. Patients in this study (n = 1445) were followed over a mean follow-up period of (mean +/- SD) 874 +/- 805 days. There were 563 episodes of AF/AFL detected, with 200 episodes resulting in inappropriate shock therapy. Overall, 745 patients received statin therapy and 700 did not. The use of statin therapy was associated with an adjusted hazard ratio of 0.472 [95% confidence interval (CI), 0.349-0.638, P < 0.001] for the development of AF/AFL with shock therapy and 0.613 (95% CI, 0.496-0.758, P < 0.001) without shock therapy when compared with the group without statin use. CONCLUSION Among a cohort with ICDs at high risk for cardiac arrhythmias, statin therapy was associated with a reduction in AF/AFL tachyarrhythmia detection and inappropriate shock therapy.

The Gender-Paradox among Patients with Implantable Cardioverter-Defibrillators: A Propensity-Matched Study

Several meta‐analyses of the implantable cardioverter‐defibrillator (ICD) clinical trials have demonstrated that while men derived a mortality reduction with prophylactic ICD implantation, women did not. These trials also observed that women receive less appropriate ICD shock therapy compared to men. We aimed to investigate this “gender‐paradox” among a heterogeneous community cohort of patients receiving ICDs.

Association between statin use and mortality in patients with implantable cardioverter-defibrillators and left ventricular systolic dysfunction

BACKGROUND A few previous nested cohort trials have evaluated the use of statins on survival and the occurrence of ventricular tachycardia or fibrillation (VT/VF). While the studies generally agreed on the survival effects, they disagreed on the magnitude of the mortality benefit and on the effect on VT/VF. OBJECTIVE The purpose of this study was to determine in a large, long-term follow-up cohort whether statin therapy could reduce mortality and the occurrence of VT/VF in a mixed population receiving an implantable cardioverter-defibrillator (ICD) for primary or secondary prevention and either ischemic or nonischemic cardiomyopathy. METHODS Cohort evaluation of all patients undergoing implantation of an ICD with a left ventricular ejection fraction <40% at an urban U.S. teaching hospital from December 1997 through January 2007. Multivariable analysis of predictors of mortality and VT/VF were conducted. RESULTS There were 314 deaths among the 1204 patients (26.1%). The use of statin therapy (n = 642) was associated with an adjusted hazard ratio of 0.67 (95% confidence interval [CI] 0.53-0.85; P<.001) for mortality as compared with the no-statin group (n = 562). The use of statin therapy was not associated with a reduction in the adjusted hazard ratio for VT/VF (0.85; 95% CI 0.68-1.06; P = .14). CONCLUSIONS Statin therapy is associated with a reduction in overall mortality in patients with ischemic or nonischemic cardiomyopathy with an ICD implanted for either primary or secondary prevention. The magnitude of survival benefit might have been underestimated given our inability to use statin as a time-dependent covariate.

Evaluation of the Charlson Comorbidity Index to Predict Early Mortality in Implantable Cardioverter Defibrillator Patients

Current guidelines consider the implantation of an implantable cardioverter defibrillator (ICD) a class III indication in patients with a life expectancy of <1 year. An evaluation of concomitant noncardiac conditions may identify patients whom may not derive benefit with ICD therapy. We sought to evaluate the association of the Charlson comorbidity index (CCI) on the prediction of early mortality (EM), death <1 year after ICD implant.

Stress-only myocardial perfusion imaging … it is time for a change!

Stress-only SPECT imaging has emerged as an important and viable alternative to conventional reststress SPECT protocols in selected patients. Advantages of stress-only imaging include improvements in patient convenience, reducing radiation exposure, increasing laboratory efficiency and cost containment. These important advances provided by stress-only acquisition protocols represent a more efficient use of SPECT technology and begs the question is it time for a change? Several SPECT imaging protocols are recommended by the American Society of Nuclear Cardiology which include dual and single isotope imaging protocols. Technetium (Tc-99m) radiopharmaceutical based protocols can be performed as one-day protocols as an initial stress-rest or rest-stress acquisition and are widely adopted in clinical practice. The radiation exposure from these protocols is significant at 11-18 mSv for Tc-99m tracers and 27-30 mSv for dual isotope rest thallium201/stress Tc-99m procedures. Stress-only acquisition protocols utilize a single dose of Tc-99m based radiotracer injected at peak stress (3-7 mSv) with avoidance of the rest injection if the stress acquisition is normal. Stress-only imaging reduces SPECT acquisition time by more than 50% and markedly reduces total patient time in the laboratory (Figure 1). The concept of stress-only imaging is not new as the literature extends back to the mid 1990s and early 2000s. Previous studies suggest that a normal stress result does not benefit from a rest study. However, in the era prior to attenuation correction (AC), the need for rest imaging was 50%-89% and unacceptably high. Attenuation correction procedures have been shown to substantially reduce attenuation artifact, and as a result, significantly improve diagnostic specificity. One of the first applications of attenuation correction to stress-only imaging was reported by Heller et al. In this study, 10 independent readers interpreted 90 stress-only studies in a blinded and sequential fashion: MPI first, MPI plus gated SPECT data and finally AC-MPI plus gated SPECT data. Interpreters were asked to provide diagnostic confidence (definitely normal, probably normal, equivocal, probably abnormal or definitely abnormal) as well as the perceived need for a rest study. Important findings were the following: attenuation corrected studies resulted in fewer non-definitive interpretations and significantly reduced the recommended need for a rest study. The authors also found that the need for a rest study was primarily in those patients with CAD and especially among those with a history of a prior myocardial infarction. Thus this and other studies suggest that the ideal candidates for stress-only imaging are those patients with no known CAD and if CAD is present, no prior history of a myocardial infarction or coronary revascularization procedure. In this issue of the Journal, Gemignani et al report on another application of stress-only SPECT imaging in the obese population. This important study provides evidence that the prevalence of a normal SPECT result is high among obese individuals undergoing pre-operative risk assessment prior to bariatric surgery. This conclusion is drawn from a cohort evaluation of 383 obese patients referred for preoperative risk stratification. The majority, 81% underwent an exercise MPI and 67% completed a stress-only protocol. Stress-only imaging was obtained with a single injection of 25-40 mCi of Tc-99m sestamibi or tetrofosmin with rest imaging only upon abnormal or equivocal results. Gated SPECT images were obtained with line source attenuation correction (AC), and applied in all studies, a method that has been shown to improve the diagnostic accuracy and specificity of imaging results. Overall, the referred population had an average age of 42 ± 10 years, BMI of 49 ± 8 and 83% were women. A clustering of coronary risk factors was observed among 23%-44%. It was anticipated that the cohort would demonstrate a high prevalence of CAD, when in fact the opposite was true, with only 1% with known From the Hartford Hospital, University of Connecticut School of Medicine, Hartford, CT. Reprint requests: Gary V. Heller, MD, PhD, Hartford Hospital, University of Connecticut School of Medicine, 80 Seymour Street, Hartford, CT 06102-5037; gheller@harthosp.org. J Nucl Cardiol 2011;18:836–9. 1071-3581/

The Healthcare Utilization and Cost of Treating Patients Experiencing Inappropriate Implantable Cardioverter Defibrillator Shocks: A Propensity Score Study

34.00 Copyright 2011 American Society of Nuclear Cardiology. doi:10.1007/s12350-011-9432-6

2017 Roadmap for Innovation—ACC Health Policy Statement on Healthcare Transformation in the Era of Digital Health, Big Data, and Precision Health: A Report of the American College of Cardiology Task Force on Health Policy Statements and Systems of Care

Inappropriate shocks (IASs) from implantable cardioverter defibrillators (ICDs) are associated with decreased quality of life, but whether they increase healthcare utilization and treatment costs is unknown. We sought to determine the impact of IASs on subsequent healthcare utilization and treatment costs.

The prognostic impact of pre-implantation hyponatremia on morbidity and mortality among patients with left ventricular dysfunction and implantable cardioverter-defibrillators

Dharam J. Kumbhani, MD, SM, FACC, Chair Cathleen Biga, MSN, RN, FACC Thomas J. Lewandowski, MD, FACC Thomas M. Maddox, MD, MSc, FACC James K. Min, MD, FACC Michael J. Wolk, MD, MACC Healthcare transformation is the product of a shared vision between a broad range of stakeholders to