Antiarrhythmic Therapy in Elderly Persons
The management of ventricular arrhythmias in elderly persons has undergone a dramatic evolution over the past 10 years. Although life-threatening arrhythmias in elderly persons have been traditionally managed with a variety of pharmacologic agents, this population presents special challenges from pharmacokinetic and pharmacodynamic perspectives. Drug absorption, distribution, metabolism, and efficacy are often altered in elderly patients, resulting in a substantially narrowed therapeutic window. Nonpharmacologic therapy for ventricular arrhythmias has the advantage of not being subject to changes in metabolism, and due to recent technological advances in transvenous lead design as well as improved programming flexibility and reduction in device size, device-based therapy for malignant ventricular arrhythmias has become more attractive for use in elderly patients. Several recent studies have suggested that device-based therapy provides superior protection from malignant arrhythmias for both primary and secondary prevention indications. The majority of these studies suggest that the benefits of device-based therapy are conferred to patients independent of age. In addition, the complication rate of such therapy appears to be independent of age.

The management of malignant ventricular arrhythmias in elderly persons has become increasingly more important as the population in the United States has aged. The Wall Street Journal reports that the fastest-growing portion of the US population are persons older than 80 years of age. It is anticipated that persons older than 85 years of age will represent 5% of the US population by the year 2050, and the number of persons aged 65 years or older by that time will total 80 million or ≈20% of the population. These changing demographics are in part the result of the doubling of life expectancy that occurred during the past century (from an average of 40 years to more than 80 years), as well as aging of the so-called post-World War II baby boom generation. In this setting, the management of cardiovascular disease remains a challenge, representing numerically the most important cause of death in the United States, outnumbering deaths attributed to cancer by a 2:1 margin. Despite evidence of declining mortality over the past 20 years, coronary artery disease (CAD) remains the leading cause of death in the United States; approximately five out of six deaths due to cardiovascular disease occur in the segment of the population that is older than 65 years of age; this age group also accounts for approximately two thirds of myocardial infarctions. Congestive heart failure (CHF) represents an additional substrate for malignant ventricular arrhythmias, with both hospitalizations and deaths related to CHF having doubled in the past 20 years. Currently, CHF is the leading admission diagnosis for persons older than 65 years of age. Given the present and projected incidence of CAD and CHF in the general population, the need for effective identification and treatment of patients at risk for malignant arrhythmias will remain paramount in the coming years.