EP Lab Digest - April 2008 - (Page 16)

16 EP 101: CONSIDERATIONS FOR THE ELDERLY EP PATIENT Continued from cover EP APRIL Elderly patients, specifically octogenarians and nonagenarians, are underrepresented in clinical trials of cardiovascular disease. They are, in fact, often excluded in these trials and are less likely to have appropriate cardiac investigations. Age alone should not be sufficient criteria to exclude a patient from an interventional therapy. Clinical considerations such as estimated risk of sudden cardiac death, degree of symptoms, and other noncardiac comorbidities may be more important in the clinical decision. Device Implantation In addition to a growing elderly population, the indications for implantable cardiac devices continue to expand. As a result, more devices are being implanted in older patients. Patients undergo implantation of permanent pacemakers for the treatment of bradyarrhythmias, ICDs for the primary and secondary prevention of sudden cardiac death, and biventricular pacemakers and/or defibrillators for the treatment of congestive heart failure. Pacemakers The natural aging process lends itself to degeneration and malfunction of the important components of the conduction system, specifically the sinus node and atrioventricular node. Disease of these structures often manifests in a dramatic fashion in the elderly as syncope or even as falls that may seem mechanical in nature. The risk of fall is confounded in a population that may have degenerative skeletal disease, reduced reaction time, reduced muscle mass or may be taking anticoagulants for conditions such as atrial fibrillation. Permanent pacemakers are extremely effective in treating bradyarrhythmias such as sick sinus syndrome and heart block, and these devices are commonly implanted in this age group. Defibrillators The mortality benefit of ICDs has been demonstrated in patients with both ischemic and nonischemic cardiomyopathies in various trials. For example, the MADIT II study revealed that there is a survival benefit to ICDs in patients with a history of myocardial infarction and left ventricular dysfunction (left ventricular ejection fraction < 30%). The mean age of those who received an ICD was 64 years. However, older elderly patients have a shorter life expectancy as a result of a high incidence of non-arrhythmic and non-cardiac death. It is not clear that the survival benefit extends to older patients with a more limited lifespan. Thus far, retrospective data suggests that the benefit of ICDs may be extrapolated to older elderly patients. In a MADIT II substudy, a trend towards improved survival with a higher risk reduction in total mortality was noted in patients older than 75 years. Of course, not all older patients are the same; it is a heterogeneous group. There is obviously a portion of patients who have a substantial burden of comorbidities such as chronic pulmonary disease, diabetes mellitus, chronic kidney disease or cancer. Patients with a terminal illness with a life expectancy not exceeding six months do not benefit from ICD therapy and should not be implanted. On the other hand, there is also a group of older patients who remain free of significant limitation from physical or mental disability.Therefore, the decision to implant an ICD in an elderly patient, as with any patient, must be made on an individual basis. For any patient, the informed consent process is a vital one. However, the issue of competence is a particularly important consideration in the elderly, since there is a higher incidence of dementia in older patients. It is important for the health care provider who is consenting the patient to explain the risks and benefits of the procedure as well as long-term consequences. Moreover, the patient must be capable of understanding these risks and benefits. The physical and psychological impact of an implantable device and subsequent shocks, real or “phantom,” can be traumatic. Complications of Device Implants There are a few complications that are worth addressing in the elderly population. Pneumothorax is more likely in patients over the age of 75 years. Attention to surgical technique, such as cephalic vein access, rather than subclavian venous puncture, is important in avoiding this complication. Infection is a major concern in any invasive procedure, especially when hardware is implanted in the endovascular space. Elderly patients with a weaker immune system may be more susceptible to infections. In addition, the breakdown of skin, which serves as a natural barrier to bacteria, may also increase the susceptibility to wound infections. If a device is being upgraded, in other words, if there is an additional wire or two being added, then a venogram is often performed in order to demonstrate patency of the venous system to be used for access. A venogram is also usually performed during the placement of the left ventricular lead in a branch of the coronary sinus for biventricular pacemakers/defibrillators. The administration of intravenous contrast is an important consideration in elderly patients, as even a small amount may impact their kidney function. Older patients may have an elevated creatinine, and they have a decreased glomerular filtration rate. Therefore, it is important to minimize the dye load and to monitor their kidney function post-operatively. Radiofrequency Catheter Ablation The treatment of cardiac arrhythmias involves the use of medications as well as catheter ablation. However, elderly patients are often approached in a conservative manner, favoring medical management rather than invasive therapy. In some patients, particularly those with multiple comorbidities, a noninvasive approach may be reasonable. On the other hand, one should understand that medications are not, as a rule, the safest option. Anti-arrhythmic agents are associated with a higher incidence of toxicity in older patients due to altered drug distribution, metabolism, and excretion, especially in patients with baseline liver or kidney abnormalities. Therefore, elderly patients are at a greater risk of proarrhythmic side effects as well as other adverse effects. Long-term medication side effects may be avoided by offering a potentially At present, elderly patients should be approached under the same guidelines as younger patients. curative catheter-based procedure. These procedures are often withheld from the elderly. Again, age alone should not be used to determine management. It is important to understand the burden of symptoms, the pathophysiology of the arrhythmia, pharmacokinetics of medications, complication rates and procedure outcomes in order to choose an optimal treatment strategy. As expected, structural heart disease is more prevalent in elderly patients as compared to young adults. In addition, older patients are at higher thromboembolic risk. These findings do not necessarily translate into a higher incidence of procedural complications, especially in right-sided radiofrequency ablations. Common arrhythmias for which catheter ablation is performed in the elderly population include typical cavotricuspid isthmus-dependent atrial flutter and AV nodal reentry tachycardia (AVNRT). In addition, ablation of the AV junction (and pacemaker implant) is often performed for patients with atrial fibrillation (AF) and rapid ventricular rates that are refractory to medical therapy. Ablation of accessory pathways or ectopic atrial tachycardias is less common in this age group. The development of new technologies and routine applications of these procedures have resulted in high success rates, up to 97% success, and a low incidence of serious complications, regardless of age. The more common complications such as groin hematomas and minor vascular complications are relatively benign and are usually managed conservatively. It is worthwhile to discuss AF treatment options in greater details since it is an extraordinarily common arrhythmia in this patient population. The prevalence of AF in a population of patients aged less than 50 years is <1%; whereas, it is 8–10% of a population of patients aged greater than 80 years. In the United States, approximately onehalf of patients with AF are greater than 70 years of age. It is noteworthy that elderly patients have been, for the most part, excluded from studies of catheter ablation for atrial fibrillation. It is a leftsided procedure that presents an inherently high risk of stroke and cardiac perforation than a right-sided procedure. With the above caveat in mind, elderly patients should be approached under the same guidelines as younger patients. A patient is a candidate for ablation of AF if they are symptomatic and if they have failed an antiarrhythmic medication. There is no data to support ablation with the goal of discontinuing warfarin. The assessment of

Table of Contents Feed for the Digital Edition of EP Lab Digest - April 2008

EP Lab Digest - April 2008 Pediatric Electrophysiology Medical Relief Work on the Yucatan Peninsula: A Labor of Love EP 101: Considerations for the Elderly EP Patient Contents Letter from the Editor Spotlight Interview: University of Maryland A Summary of the ACC/AHA/Physician Consortium 2008 Clinical Performance Measures for Adults with Nonvalvular Atrial Fibrillation or Flutter Can Psychosocial Characteristics Predict Fatal Outcomes in Patients? Interview with Jonathan S. Steinberg, MD, FACC 10-Minute Interview: Diane D. Sheffield, RN, BSN AED Access for All: An Organization for SCA Survivors New Column: 5 Quick Clues to AV Nodal Reentry Tachycardia CMS 2008 OPPS Final Rule Review New Online AED and CPR Training Opportunities: Q & A with Keith Weaver Highlights from the 5th Annual International Arrhythmia Winter School Email Discussion Group Events Calendar Second Annual Salary Survey Industry News and Products Classifieds Advertisers Index

EP Lab Digest - April 2008

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