Heart disease in the elderly

The average US life expectancy is 76 years for men and 81 years for women. Elderly in the context of most clinical guidelines refers to patients age 65 years or older. There is variation arising from different age limits used in clinical trials such as 75 years or older or 80 years or older to describe very old, as well as subcategorizations into nonagenarian and centenarian. In this chapter, we refer to elderly as patients age 65 years or older with special consideration for different age groups highlighted in the individual sections. However, for the future, we believe that age older than 75 years may be a better definition to define the elderly, as many individuals are still actively working in their late 60s. Cardiovascular disease (CVD) remains the leading cause of mortality (164 deaths per 100,000) in the United States and increases with age. More than 70% of US adults develop CVD by the age of 79 years.

The CVD risk profile and CVD outcomes among the elderly are strongly influenced by frailty, comorbidities, and individualized goals of care, beyond their cardiovascular risk profile. In many clinical trials, the elderly are underrepresented, leaving significant knowledge gaps in understanding treatment effects and risk among this population group. Reasons for this include frailty, fall risk, poor renal function, postural hypotension, cognitive impairment, and perceived limited life expectancy. These factors play key roles in shaping treatment strategies and require thorough assessment.

It is important to dose medications appropriately with attention to dose adjustments based on age, weight, hepatic, and renal function. Renal function should be estimated by calculating an estimation of creatinine clearance (CrCl) using the Cockroft-Gault equation or Modification of Diet in Renal Disease (MDRD) equation to provide the estimated glomerular filtration rate (GFR) rather than utilizing creatinine alone. Elderly patients may have a near-normal serum creatinine but still have significant renal impairment as a result of sarcopenia. In addition, when starting a new medication, it is important to consider the proper dose, as well as continuous reassessment and monitoring for potential drug-drug interactions and drug adherence that may be limited by poor cognitive function, adverse drug events, and patient goals ( Fig. 51.1 ).

Both initiation and continuation of antihypertensive therapy is recommended in the elderly. Among the elderly, 2017 American College of Cardiology/American Heart Association (ACC/AHA) guidelines recommend initiating pharmacologic therapy for blood pressure greater than or equal to 130/80 mm Hg with a target blood pressure less than 130/80 mm Hg among patients age 65 years or older. In patients older than 75 years of age at increased risk of heart failure (HF), a systolic blood pressure goal of less than 120 mm Hg is recommended and is associated with a lower incidence of HF and cardiovascular death in the Systolic Blood Pressure Intervention Trial (SPRINT) trial (hazard ratio [HR] 0.62; 95% confidence interval [CI] 0.45–0.84). Of note, a higher target for therapy (≥160/90) is recommended in the European Society of Cardiology (ESC) 2018 guidelines for the initiation of pharmacotherapy among patients age 80 years or older. Among poststroke patients, where cerebral perfusion may be compromised, the AHA/American Stroke Association (ASA) 2014 guidelines for stroke prevention recommend that a target blood pressure of 140/90 mm Hg would be reasonable. It is recommended to start with lower initial drug dosages and slower medication titration with close monitoring for side effects including postural hypotension, syncope, electrolyte abnormalities, and acute kidney injury.

Statin therapy reduces the risk of major vascular events by 25% in those without clinical atherosclerotic cardiovascular disease (ASCVD) as demonstrated in the Cholesterol Treatment Trialists’ Collaboration. Pooled cohort equations are recommended to calculate 10-year atherosclerotic cardiovascular risk for patients 40 to 75 years of age. For elderly patients (>75 years of age), where representation in clinical trials of lipid-lowering therapy has been poor, the relative lifelong benefit is uncertain. In general, the elderly are at the highest risk of CVD events, and with increasing life expectancy, derive greater absolute benefit.

In patients 75 years or older, the 2018 ACC/AHA blood cholesterol guideline recommends initiating a moderate-intensity statin for primary prevention for a low-density lipoprotein-cholesterol (LDL-C) level 70 to 189 mg/dL and stopping when functional decline, multimorbidity, frailty, or reduced life expectancy limits the potential benefits of therapy ( Table 51.1 ).

In a meta-analysis of individual participant data from 28 randomized controlled trials analyzing efficacy and safety of statin therapy in older individuals, statins therapy was significant in reducing major cardiovascular events regardless of age. This finding corroborates the 2018 ACC/AHA blood cholesterol guideline recommending the use of moderate- or high-intensity statin therapy for secondary prevention in individuals greater than 75 years of age with clinical ASCVD. Continuation of statin therapy is also recommended after evaluation of the potential for ASCVD risk reduction, adverse effects, and drug-drug interactions, as well as patient frailty and patient preferences.