Journal of Invasive Cardiology

Technical Factors
The technical feasibility of PCI in the elderly has been well studied. Initial success rates range from 92–99%, and the success rate is high, even for very old patients. In the BARI trial,²³ the five-year survival rate with angioplasty was similar to that with bypass surgery although, as found in the total study group, diabetics have a better survival rate when treated with bypass surgery. Mortality and morbidity rates with PCI are highest for the elderly population because the patients are frail and have more advanced disease. Also, in older patients, the occurrence of any procedural complication is associated with subsequent mortality.
Specific technical considerations often cited in elderly patients include heavier coronary calcification, tortuous anatomy in both coronary and vascular approaches, and higher cerebral, renal and pulmonary morbidities. The heavier calcification, in general, frequently renders technical aspects of the procedure more difficult and may lead to increased utilization of ablative devices, such as in rotational atherectomy procedures. Renal dysfunction and anemia, often of ill-defined cause, result in reduced tolerance to bleeding complications. Peripheral vascular disease with a tortuous aorto-iliac system and often subclavian vessels may significantly affect access for interventional procedures.
Adjunctive anticoagulation in the catheterization laboratory has to be considered separately in the elderly. In REPLACE-2,²⁵ bivalirudin was more efficacious in the > 75-year-old subgroup (2.5% reduction in primary endpoint, 15.2% vs. 12.7%) than in those < 75 years of age (0.5% reduction; 9.2% vs. 8.7%); again, however, the absolute risk remained higher. Similarly, in ESPRIT,26 the treatment effect of integrelin in those aged > 65 years was greater compared to those < 65 years of age (1.7% reduction at 48 hours; 8.1 vs. 6.8% vs. 7.2% reduction; 13.7% vs. 6.5%).

Physiological Considerations
The prolonged effect of risk factors on the vascular system leads to a more extensive pattern of atherosclerosis in coronary and other vascular areas. Increased vascular stiffness leads to systolic hypertension and greater left ventricular afterload, resulting in left ventricular hypertrophy and diminished left ventricular function. As a consequence of aging and/or systolic hypertension, the myocardium develops impaired and delayed early diastolic filling. Endothelial dysfunction is predominant, especially in the coronary bed. Both coronary and muscular adrenergic receptors exhibit decreased responsiveness. There is a loss of the benefit of ischemic preconditioning. Finally, there is increased apoptosis and decreased angiogenesis. How these known physiologic effects of aging²⁷ specifically relate to the anticipated outcomes of PCI has not been evaluated in a clinical study, nor has their physiologic significance been evaluated in conjunction with altering technical details of the procedure (e.g., balloon inflation time, contrast load, etc.).