Despite Challenges, Coronary Revascularization Benefits the Elderly

Issue: November/December 2017

ByCindy L. Grines, MD

ByRaghav Sharma, MD

The current rate at which the U.S. population is aging is remarkable. Increasing life span and the baby boomer generation will double the number of Americans aged 65 years and older in the next 25 years to upward of 72 million, according to a 2013 report from the CDC. Heart disease continues to be the leading cause of death in the U.S. population and, therefore, it is essential that we understand the trends in coronary artery revascularization in the elderly.

The Complicated Older Patient

The elderly population presents in a complex and challenging manner to the clinician. They present with atypical symptoms in the setting of multiple comorbidities. As the body ages, there is a reduction in lean body mass, relative increase in body fat, polypharmacy, decreased renal function and changes in gut motility, thus putting the elderly population at risk for significant side effects from standard medical therapy.

The inability to tolerate a wide spectrum of medications along with underrepresentation in prospective clinical trials further exposes the aging population to substandard levels of care.

Effects of Aging on Arteries

The natural process of aging results in intrinsic changes in the myocardium and cardiac vasculature. Over time, the coronary arteries become dilated, tortuous, and develop diffuse and localized calcifications, ultimately leading to impaired endothelial function. Increased arterial and aortic stiffness results in increased afterload, which over time increases myocardial thickness. Progression of myocardial remodeling leads to increased fibroelastic changes in the ventricles, thereby initially worsening diastolic ventricular function and increasing left ventricular end-diastolic pressure (LVEDP). Subjected to prolonged periods of increased LVEDP, the noncompliant left ventricle begins failing, resulting in decreasing ejection fraction and cardiac output.

If identified early, the ischemic cascade may be altered by appropriate noninvasive testing and possible intervention. However, significant bias in appropriately testing and, ultimately, intervening on the elderly exists, thereby exposing the population to a preventable progression of CAD.

PCI in the Elderly

A review of more than 1 million patients in the National Cardiovascular Data Registry (NCDR) from 2010-2011 demonstrated that of all patients who had a diagnostic angiogram and PCI, only 12% of the population was older than 80 years (Figure 1), whereas the incidence of CAD in men and women older than 85 years is 43% and 45%, respectively, with the incidence of acute MI being more than threefold in patients older than 75 years in 2007 vs. the younger population. The hesitation of operators about performing PCI on the elderly likely stems from studies demonstrating increased rates of CVD, renal failure, HF, bleeding and death in the elderly after PCI. However, the risk for adverse events in the elderly are mitigated by the clear benefit of invasive strategy in patients aged at least 65 years, demonstrating a RR reduction of 0.66 and overall reduction of 0.61 vs. conservative medical therapy in patients with ACS (Figure 2). PCI has also demonstrated benefit in 30-day event rates in patients older than 70 years vs. lytic therapy.

**Figure 1.** Breakdown by age group of U.S. diagnostic angiograms and PCIs, 2010-2011.

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Similarly, the After Eighty study randomly assigned patients with ACS aged at least 80 years to invasive vs. noninvasive strategy. The study demonstrated improved survival and MACE in the invasive strategy group (P = .009). Likewise, the TIME trial randomly assigned patients older than 75 years with stable angina and found improved event-free survival with an invasive approach vs. medical therapy (P < .0001).

Current questions are how to define “the elderly population” with age cutoffs ranging from 65 to at least 80 years, and whether PCI or CABG is more beneficial in elderly patients.

CABG in the Elderly

Complications from CABG performed in octogenarians were found to be less than previously reported, especially with CABG alone or CABG with aortic valve replacement. When appropriate preoperative selection is made, patients aged at least 80 years had fewer comorbidities, shorter cross-clamp time, lower use of internal mammary artery grafts, similar rates of complete revascularization and mortality vs. the younger population. When comparing multivessel PCI vs. CABG in the elderly, mortality rates remain acceptable and similar in first 3 years.

The question remains: What prompts surgeons and interventionalists to decide when to subject the elderly population to CABG vs. PCI if the mortality rates remain similar? In one study, the label of “surgical ineligibility” was frequently cited for the reason to defer CABG, and it was associated with a fivefold increased risk for mortality independent of accepted risk assessment scores. A more methodical approach to determining which patients are at higher risk is to use objective scoring systems to assess comorbidities (Charlson index), quality of life (SF-36 questionnaire) and frailty (Fried criteria). When utilizing these scoring systems, 3-year mortality rates for frail patients were significantly increased.

Advancing Understanding

Coronary revascularization in the elderly has shown to improve outcomes in both stable angina and ACS, including STEMI. As the population ages, the complications from PCI and CABG expectedly increase. However, with careful and methodical selection, elderly patients may have similar mortality and complication rates vs. the younger population.

Despite the paucity of clinical trials representing the elderly population, advancements of technology leading to clear benefits in cardiology interventions challenges the younger and current generation of cardiologists to adapt and apply these techniques to the maturing population.

**Figure 2.** Invasive strategies are linked to better outcomes vs. conservative strategies in patients aged 65 years and older.

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For more information:
Raghav Sharma, MD, is chief cardiology fellow at Hofstra Northwell School of Medicine, Northwell Cardiology.
Cindy Grines, MD, is chair of cardiology at Hofstra Northwell School of Medicine, academic chief of cardiology at Northwell Health and interventional cardiologist at the Sandra Atlas Bass Heart Hospital at North Shore University Hospital. The authors can be reached at rsharma6@northwell.edu.

Disclosures: Sharma and Grines report no relevant financial disclosures.