Should this patient receive an implantable cardioverter defibrillator?

November 5, 2008
Cardiology Review® Online, September 2007, Volume 24, Issue 9

An 83-year-old woman with ischemic cardiomyopathy and a left ventricular ejection fraction of 27% was hospitalized with increasing shortness of breath and lower extremity edema.

An 83-year-old woman with ischemic cardiomyopathy and a left ventricular ejection fraction of 27% was hospitalized with increasing shortness of breath and lower extremity edema. The patient denied chest discomfort, paroxysmal nocturnal dyspnea, palpitations, or syncope. She reported compliance with dietary restrictions and all medications, which included daily furosemide (Lasix) 40 mg, lisinopril (Prinivil, Zestril) 40 mg, spironolactone (Aldactone) 12.5 mg, digoxin (Lanoxin) 0.125 mg, atorvastatin (Lipitor) 40 mg, and aspirin 81 mg, along with carvedilol (Coreg) 12.5 mg twice daily.

The patient's medical history was notable for 2 previous hospitalizations for worsening heart failure in the past 12 months; myocardial infarction (MI) was excluded on both occasions. She had 2 previous MIs and underwent 4-vessel coronary bypass surgery 8 years earlier. She also had a history of peripheral arterial disease, hypertension, dyslipidemia, and arthritis.

Physical examination showed an elderly woman in mild respiratory distress. Her heart rate was 96 beats/ minute and regular, and her blood pressure was 110/60 mm Hg. The jugular venous pressure was approximately 15 cm H20, and bilateral pulmonary crackles were noted over the lower half of both lung fields. An S3 gallop and II/VI apical holosystolic murmur were noted. The abdomen was soft, with mild hepatomegaly. Moderate pitting edema was present to the level of the midcalves. The patient's mental status was intact, and no focal neurologic deficits were elicited.

An electrocardiogram showed sinus rhythm with left bundle branch block, and a chest radiograph showed moderate cardiomegaly, bilateral perihilar infiltrates, and small bilateral pleural effusions. Laboratory results showed the following values: serum sodium, 133 meq/L; potassium, 3.7 meq/L; creatinine, 1.4 mg/dL; serum urea nitrogen, 41 mg/dL; hemoglobin, 11.6 g/dL; and white blood cell count, 9.3 x 103/mL; B-type natriuretic peptide, 1081 pg/mL. Serial troponin I levels were normal.

The patient was treated with intravenous furosemide with prompt diuresis. Her spironolactone dose was increased to 25 mg daily, and her carvedilol dose was increased to 25 mg twice daily. By the third hospital day, her breathing and edema were much improved, and she was ambulating in the hall without difficulty. Her son, a pathologist in another city, stated that he was concerned about his mother's recurrent hospitalizations for heart failure and inquired about her prognosis, in particular, whether she should receive an implantable cardioverter defibrillator (ICD). How would you advise him?

Based on the findings of our recent study, this patient has 5 risk factors for mortality: age over 75 years, coronary heart disease, peripheral arterial disease, low systolic blood pressure, and hyponatremia. This places her in the highest risk category, with projected 6-month, 1-year, and 5-year mortality rates of 60%, 73%, and 100%, respectively. It would therefore be appropriate to indicate to the patient's son that although it is difficult to predict how long his mother might survive, her overall prognosis is poor; she has less than a 50% chance of surviving 6 months and only a 25% chance of surviving 1 year. In addition, because the ICD has not been shown to improve outcomes during the first year, placement of an ICD in this patient is inadvisable. Thus, this case illustrates the potential value of the heart failure mortality risk score in providing useful prognostic information for elderly patients and their families, and as an aid in guiding therapeutic decision making.