Does increased stress lead to heart attack?
Does stress kill the heart? Probably, but let’s explore why.
Several high-quality studies have attempted to draw a link between stress and cardiac health. Since stress is a difficult concept to define and reproduce across study subjects, clinical trials have struggled to qualify the relationship between heart disease and stress. But, there certainly appears to be a link between psychological stress and both incidence of acute myocardial infarction (MI) and incidence of risk factors associated with MI.
The largest study to examine stress and cardiac disease was the INTERHEART study, a case-control study from 52 countries that examined over 11,000 cases of acute MI and 13,000 controls. Based on a simplified scale for stress at work or home and financial stress, the study found that over one-third more MI sufferers than controls experienced several periods of stress at home or work, and twice as many cases than controls experienced permanent stress at work or home (OR: 1.38, CI: 1.3-1.61 and 2.17, CI: 1.84-2.55, respectively) (Lancet 2004; 364:953-62). This work reinforces smaller studies performed in single countries among smaller cohorts of patients (BMJ 2002; 325:857, Int J Epidemiol 2003; 6:990-7).
Several disease processes that are significant risk factors for coronary artery disease and MI are also more common among patients with chronic stress. The metabolic syndrome is a cluster of risk factors that includes three of the following: abdominal obesity, elevated triglycerides, suppressed HDL cholesterol, elevated blood pressure, and elevated fasting glucose. A prospective study of over 10,000 English patients found the metabolic syndrome to be twice as common among those who reported higher exposure to work-related stress (OR: 2.29, 1.27-4.12) (BMJ 2006 332:521-5). Similarly, multiple studies have found that chronic stressors at work or panic disorder can lead to increased rates of hypertension (J Psychosom Res 1999; 46:215-27, Am J Med 1999; 107:310-6).