MD Conference Express ACC 2012 - (Page 18)
SPONSORED SESSION HIGHLIGHTS
American College of Cardiology 61st Annual Scientific Session
Risk for Sudden Cardiac Death After PCI or CABG
Sunil V. Rao, MD, Duke University Medical Center, Durham, North Carolina, USA, discussed the risks of sudden cardiac death (SCD) following percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) surgery, as well as treatment options to reduce those risks - particularly in the vulnerable window immediately following the procedures. The risk for SCD in patients who are post-myocardial infarction (MI) or post-revascularization (whether by PCI or CABG) is highest in the first 30 days post-event, including mortality.1 A feature that is common to these high-risk patients is a low ejection fraction (EF). Post-MI patients who present with left ventricular dysfunction, heart failure, or both, have a 4 to 6 times greater risk than those without these complications.2,3 In the setting of PCI, low left ventricular ejection fraction (LVEF) is a significant predictor of SCD during recovery from revascularization,1,4,5 with baseline LVEF being the most powerful predictor of mortality.1 Even though there is more complete revascularization with CABG compared with PCI, the peri- and post-surgical risks for SCD are similar. Toda et al showed that 6% of postPCI patients with low LVEF will experience ventricular tachycardia or ventricular fibrillation/ (VT/VF) within 30 days; while 7% of patients who await CABG and 10% of patients 30 days post-CABG experience VT/VF.5 “High-risk patients are going to be at risk of SCD even after optimal revascularization, which is something interventional cardiologists need to be more aware of,” reminded Dr. Rao. For patients who are undergoing CABG, the highest risk of SCD occurs in the first 90 days post-surgery. Preoperative LVEF ≤30% is associated with a higher risk of SCD in that same period.6 The 3-month post-CABG death rate following a ventricular arrhythmia is 6%.6 The use of an implantable cardioverter defibrillator (ICD) can significantly reduce the rate of SCD in at-risk patients. However, the guidelines for implanting ICDs impose a waiting period that ranges from 40 days after MI to 90 days after PCI or CABG. Unfortunately, it is during this waiting period that patients are at their highest risk of sudden cardiac arrest. Optimal medical therapy (OMT) results in significant improvements in EF. In the REFINE study, a 19% relative (8% absolute) increase in mean LVEF was observed over the initial 8 weeks after MI overall (t test p<0.001) in patients who received OMT.7 However, OMT is difficult to achieve. The ADHERE registry showed that only half of all HF patients receive the correct medications as outpatients.8 In addition, long-term adherence rates to evidence-based secondary prevention (aspirin, beta-blockers, and/or lipid-lowering agents), although improving over time, remain suboptimal and improved discharge prescription of these agents is needed.10 A study that was conducted at Duke followed 2776 patients with significant coronary disease who were turned down for revascularization for a variety of reasons and were then treated with OMT for 5 years.9 The results showed very high rates of adverse events-- after 5 years, almost 80% of these patients experienced death, MI, cardiac rehospitalization, or late revascularization. Wearable Cardioverter Defibrillators A wearable cardioverter defibrillator (WCD) is another option for adult patients who are at risk for SCD and who may be in a waiting period for ICD implantation, or are not candidates for, or who refuse, an implantable defibrillator. WCDs are included in the American College of Cardiology/ American Heart Association/European Society of Cardiology 2006 Guidelines for Management of Patients with Ventricular Arrhythmias and Prevention of Sudden Cardiac Death,11 the 2006 International Society for Heart and Lung Transplantation Guidelines for the Care of Cardiac Transplant Candidates,12 and the Transvenous Lead Extraction: Heart Rhythm Society Expert Consensus on Facilities, Training, Indications, and Patient Management , and the Heart Rhythm Society Sudden Cardiac Death Primary Prevention Protocols (Figure 1).13 Figure 1. Sudden Cardiac Death Primary Prevention Protocols.
EF ≤ 35% for Non-Ischemic Cardiomyopathy 40% for Ischemic Cardiomyopathy
Any Cardiomyopathy Not on Optimal Medical Therapy
Post-MI or Ischemic Cardiomyopathy With Revascularization (PCI or CABG); ICD Waiting Period >90 days
Post-MI Without Revascularization ICD Waiting Period >40 days
Any Cardiomyopathy Beyond ICD Waiting Period on optimal medical therapy
Initiate or Titrate Medical Therapy β Blocker - ACE/ARB - Aldosterone Antagonist
Discharge Home Consider wearable cardioverter defibrillator; Continue optimization of medical therapy
Reassess EF at 90 days
Reassess EF at 40 days
Non-ischemic cardiomyopathy EF≤35%
Ischemic Cardiomyopaythy
EF=36%-40% → Consider further risk stratification EF≤35%
Refer for Consideration of ICD
PCI=percutaneous coronary intervention; CABG=coronary artery bypass grafting; ICD=implantable cardiac defribrillator; EF=ejection fraction.
Reproduced with permission from the Heart Rhythm Society. All rights reserved. Copyright © 2012.
A recent observational study evaluated the benefit of using a WCD in patients (n=530) with low EF following PCI (n=530) or CABG (n=404).14 PCI patients who were prescribed a WCD
This peer-reviewed article was based on an Industry Expert Theater presentation from the ACC 2012 Scientific Session. The development of this advertorial was supported by ZOLL.
Table of Contents for the Digital Edition of MD Conference Express ACC 2012
MD Conference Express ACC 2012
Table of Contents
Treatment of AMI in the Post-Herrick Era
The State of Hypertension Guidelines: 2012
ACRIN PA 4005: Coronary CTA in the ED Identifies Low-Risk Patients and Shortens Length of Stay
One-Year STAMPEDE Trial Results
TAVR Associated with Increased Late Mortality from Paravalvular Regurgitation
The CABG Surgery Off- or On- Pump- Revascularization Study (CORONARY)
The Moderate PE Treated with Thrombolysis Study (MOPETT)
Pacemaker Therapy In Patients With Neurally Mediated Syncope and Documented Asystole
Outcomes from the BRIDGE-ACS Trial
ROMICAT II: More Data Evaluating CT-First for Acute Chest Pain ED Triage
Elective PCI at Community Hospitals With Versus Without On-Site Surgery
Results from the TRA 2P-TIMI 50 Trial
The HOST-ASSURE Randomized Trial
New Monoclonal Antibody to PCSK9 Markedly Lowers LDL-C in Patients on Atorvastatin
Oral Rivaroxaban Alone for Symptomatic PE
Neutral Outcomes But Important Insights From FOCUS-CCTRN
Imaging
STEMI
Acute Coronary Syndrome
Antiplatelet Therapy
New Anti-Diabetes Agents Offer Promise in the Fight Against CVD
The New Hypertrophic Cardiomyopathy Practice Guidelines
MD Conference Express ACC 2012
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