An 84-year-old man is referred to your clinic for primary prevention implantable cardiac defibrillator (ICD) implantation. Medical history includes distantly revascularized coronary artery disease with a current ejection fraction of 30%, congestive heart failure (CHF) with New York Heart Association (NYHA) functional class III symptoms, stage III chronic kidney disease, hypertension, and atrial fibrillation (AF) treated with systemic anticoagulation. Over the past year, he had two admissions for heart failure decompensations. He lives with his wife of 60 years, and used to smoke but quit after a previous heart attack. He previously walked outside every day, but now is largely confined to the house due to fatigue with exertion. He still drives short distances into town, always accompanied by his wife. Medications include carvedilol, lisinopril, spironolactone, twice-daily furosemide, aspirin, atorvastatin, and warfarin. On physical examination, vitals are blood pressure 100/60 mm Hg, heart rate 65 per minute, respiration rate 16 breaths per minute, oxygen saturation 96% on room air. Body mass index is 22 kg/m2. There is no jugular venous distention, and there are no rales or wheezes upon inspiration. The heart rate is regular, and there is an S3 with a soft holosystolic murmur at the apex. Extremities are warm with mild edema. Dorsalis pedis pulse is palpable on the right foot, but not the left. He ambulates slowly (gait speed 0.6/msec) and 6 seconds are required to rise from a seated position. Pertinent labs include a hemoglobin of 10.9 g/dL, sodium of 135 mEq/L, blood urea nitrogen of 43 mg/dL, and creatinine of 1.8 mg/dL with an eGFR of 34 mL/min/1.73m2. Liver function tests are unremarkable. An electrocardiogram shows evidence of an old inferior myocardial infarction, and the QRS duration is 110 ms. An echocardiogram reveals moderately depressed systolic function with moderate left ventricular dilation, eccentric remodeling, moderate mitral regurgitation, and normal right ventricular function.
Which of the following statements is true regarding primary prevention ICD placement for this patient?
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The correct answer is: D. He is more likely to suffer noncardiac death than appropriate ICD shock at one-year.
This patient has moderately severe chronic systolic heart failure. By Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) criteria (ejection fraction ≤0.35 and class II CHF), he is a candidate for primary prevention ICD placement. Yet, the consulting physician must evaluate all the clinical data and discuss all of the options available, including the associated risks and benefits. He is elderly and frail, with comorbid chronic AF and renal insufficiency. He is still independent and happily married. Up until recently, he enjoyed a high quality of life. Now, his routine daily activities have changed due to diminished functional reserve. It would be useful to learn the patient's overall understanding of heart failure, the natural course of disease, his individual prognosis, and personal priorities. A conversation about expectations and effects of ICD placement and risks and benefits ought to occur. The consultant might convey that the majority of patients never receive a shock from their device during its lifetime.
Unfortunately, the risk of death at one-year for this older adult patient with low left ventricular ejection fraction and ≥2 comorbidities is higher than 10% (Answer B, incorrect), approximating anywhere from 20-50% by different prediction models.1,2 A poor prognosis is especially portended by the presence of significant kidney disease (CrCl <60 mL/min) and admissions for acute decompensated heart failure, both of which magnify the risk of mortality. Patients ≥70 years of age with recurrent heart failure admissions have an estimated median survival of only 1.5 years, regardless of ICD status.3 Therefore, a non-cardiac death is more likely to occur than a tachyarrhythmic sudden death that an implantable device would prevent (Answer D, correct).
In contrast to the high risk of noncardiac death, the chance of an appropriate ICD shock is relatively low, and estimated at 1% per year according to a validation analysis model that incorporates predictors of sudden cardiac death.2 Death in advanced heart failure is usually from progressive pump failure.
Data indicates that heart failure patients overestimate the benefits of ICDs and have a poor understanding of their prognosis (Answer A, incorrect). A survey of candidates for primary prevention ICD placement showed that most patients anticipated >10 year prognosis. Half of the patients believed an ICD would generally save ≥50 lives per 100 over five years.4 In reality, the diagnosis of CHF carries a 50% mortality rate at 5 years, and the majority of primary prevention ICDs do not deliver a shock prior to the first recommended replacement.
If this patient's QRS complex were left bundle branch block morphology and >150 ms duration, the decision to implant a permanent device would be more straightforward. Cardiac resynchronization therapy (CRT) reduces overall heart failure mortality (not only arrhythmic mortality), and improves both left ventricular ejection fraction and symptomatic burden, even in octogenarians.5,6 CRT is therefore the preferred device in elderly patients who meet the aforementioned indications, and who do not have elevated one-year mortality rates due to noncardiac conditions, unlike the patient in question (Answer C, incorrect).
There is conflicting data on whether in-hospital complication rates of ICD implantation itself are related to age (Answer E, incorrect). Generally, complications from ICD implantation occur ≤3% of the time, ranging from hematoma to lead dislodgement to cardiac arrest. Increased in-hospital mortality related to cardiac device procedures has been described in patients >80 years of age.7 More recently, registry reviews suggest that complication rates between the old and the young are equivalent.8 A model was developed by Dodson and colleagues to address and estimate in-hospital complication risks associated with ICD implantation. The best predictors of adverse events were symptomatic heart failure, renal insufficiency, nonelective admission, initial device implantation, and ICD type.9 For this patient, the predicted in-hospital complication rate would be >2%.
References
Goldenberg I, Vyas AK, Hall WJ, et al. Risk stratification for primary implantation of a cardioverter-defibrillator in patients with ischemic left ventricular dysfunction. J Am Coll Cardiol 2008;51:288-96.
Lee DS, Hardy J, Yee R, et al. Clinical risk stratification for primary prevention implantable cardioverter defibrillators. Circ Heart Fail 2015;8:927-37.
Setoguchi S, Stevenson LW, Schneeweiss S. Repeated hospitalizations predict mortality in the community population with heart failure. Am Heart J 2007;154:260–6.
Stewart GC, Weintraub JR, Pratibhu PP, et al. Patient expectations from implantable defibrillators to prevent death in heart failure. J Card Fail 2010;16:106–13.
Cleland JG, Daubert JC, Erdmann E, et al. The effect of cardiac resynchronization on morbidity and mortality in heart failure. N Engl J Med 2005;352:1539-49.
Killu AM, Wu JH, Friedman PA, et al. Outcomes of cardiac resynchronization therapy in the elderly. Pacing Clin Electrophysiol 2013;36:664-72.
Swindle JP, Rich MW, McCann P, Burroughs TE, Hauptman PJ. Implantable cardiac device procedures in older patients: use and in-hospital outcomes. Arch Intern Med 2010;170:631-7.
Suleiman M, Goldenberg I, Haim M, et al. Clinical characteristics and outcomes of elderly patients treated with an implantable cardioverter-defibrillator or cardiac resynchronization therapy in a real-world setting: data from the Israeli ICD Registry. Heart Rhythm 2014 ;11:435-41.
Dodson JA, Reynolds MR, Bao H, et al. Developing a risk model for in-hospital adverse events following implantable cardioverter-defibrillator implantation: a report from the NCDR (National Cardiovascular Data Registry). J Am Coll Cardiol 2014;63:788-96.
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