EP 101: Considerations for the Elderly EP Patient

The number of patients greater than 65 years of age are increasing and will continue to increase in a dramatic fashion in the United States over the next 20-30 years. As cardiologists strive to use evidence-based medicine as the foundation of clinical practice and decision-making, it is with difficulty that we do so in this particular population, especially in those over the age of 80. 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 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 non-invasive 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 pro-arrhythmic side effects as well as other adverse effects. Long-term medication side effects may be avoided by offering a potentially 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 Anesthesia and Sedation Anesthesia and sedation are administered in a number of ways: local anesthesia, conscious sedation and general anesthesia. Most endovascular procedures, including diagnostic electrophysiology studies and catheter-based ablations, can be performed safely with a combination of a local anesthetic at the site(s) of vascular access and conscious sedation. Conscious sedation is a method of anesthesia whereby patients are given intravenous medications at doses that do not require complete airway protection (i.e., endotracheal intubation). For prolonged procedures, conscious sedation may not be adequate and general anesthesia may be preferred. It may be challenging to adequately sedate and anesthetize an elderly patient in a safe manner. Elderly patients typically present with co-morbidities, including primary lung disease such as chronic obstructive pulmonary disease, which can make airway management difficult. Their ability to metabolize sedatives and painkillers is variable and often unpredictable. Procedures in these patients require clinicians and support staff expert in geriatric physiology and a preparedness to confront challenges that may arise. Older elders undergoing conscious sedation often require more prolonged observation post-operatively owing to both the reduced metabolism of these medications and the occasional atypical reaction, especially to benzodiazepines and antihistamines. General anesthesia not only presents similar medication-related challenges, but also the cardiovascular stress of induction and termination of anesthesia. In those patients with substantial underlying atherosclerotic cardiovascular disease, careful management is required to avoid hypotension and subsequent ischemic events. Sedation can be challenging, but it is not contraindicated in the elderly. Invasive procedures in these patients require a thorough screening and workup as well as expert intraoperative and postoperative staff. Conclusion Elderly patients are a large part of our cardiac electrophysiology practice. In order to choose appropriate medical strategies for these patients, we must use not only evidence-based data, as it is often lacking in this group, but also our clinical judgement to offer optimal treatments. In that way, we will consider age, but we will not use it as a sole factor in our management decision.