Mindfulness-Based Stress Reduction and Myocardial Ischemia

BACKGROUND:

Acute and chronic psychological stress has been shown to be a risk factor for cardiac events. More recently with the advent of new technology allowing cardiac imaging, acute psychological stressors have been shown to produce myocardial ischemia in certain subsets of patients with CAD. Several studies have shown that the production of myocardial ischemia in response to acute psychological stress in the laboratory is a marker for adverse events in patients with CAD. Several pathways by which psychologically induced stress may trigger ischemic events have been proposed, and a number of studies have provided evidence that stress affects ischemic events via these pathways. Stress interventions have been shown to have a positive impact on CAD outcomes, with only one thus far testing their effects on ischemic events. Furthermore, some studies have reported positive results with coronary risk factors using meditation and yoga. Current clinical meditation literature suggests that a mindfulness meditation-based stress reduction program (i.e., multicomponent, psychoeducational program based in mindfulness meditation that cultivates an ability to pay attention to one's moment-to-moment experiences in a nonjudgmental, nonreactive fashion) will be able to reduce stress reactivity in CAD patients. It is predicted that such reductions in stress reactivity will result in reduced radionuclide imaged perfusion defects during a laboratory mental stress task. Although it has not been used with heart patients, it has demonstrated good results with both stress and symptomology in the general and other medical populations. We believe that similar results will be seen in CAD patients with effects acting through the following pathways: 1) decreased sympathetic tone and 2) increased parasympathetic tone. The overall goal of the proposed study is to evaluate the efficacy of a meditation-based stress reduction program for the reduction of mental stress-induced ischemia.

DESIGN NARRATIVE:

To test the efficacy of MBSR, patients will be randomly assigned to one of three groups. The MBSR condition will be provided training in mindfulness meditation methods. The patient education control group will be provided information about CAD in a didactic format. This condition will control for the nonspecific effects of contact in a therapeutic setting. Excluding intervals spent in personal meditation practice in the mindfulness meditation condition, the length of sessions in the two intervention conditions will be approximately equal. The third group, a stress-monitoring usual care control condition, will control for the effects of symptom measurement reactivity in patients receiving routine medical care.

Inclusion criteria

• At least 18 years old
• Confirmed CAD--the clinical diagnosis of coronary disease will be defined by the presence of at least one of the following: 1) abnormal coronary angiogram; 2) abnormal intravascular ultrasound (IVUS); or 3) abnormal flow reserve and documentation of one of the following: 1) elevated troponin laboratory values typical for myocardial infarction; 2) electrocardiogram (ECG) that shows q-wave abnormalities; 3) nuclear scan that demonstrates a fixed wall motion abnormality consistent with an old myocardial infarct; 4) greater than 95% probability of coronary disease according to the criteria of Diamond and Forrester.102; 5) radionuclide study, dobutamine, or exercise echocardiographic study consistent with stress-induced ischemia (development of segmental wall motion abnormalities or reversible perfusion defects on radionuclide imaging and/or wall motion or systolic thickening abnormalities on stress echocardiographic exam)

Exclusion criteria

• Current pregnancy or probability of pregnancy during the duration of the 12-week study
• Diagnosis of unstable angina in the prior 2 months
• Presence of other severe, complicating medical problems that will significantly shorten the patients' life expectancy such that they will not be expected to live for the 12 weeks of this study
• Presence of serious psychopathology evidenced by BDI scores that indicate a clinically critical level of depression (score of 24 or above) with suicidal ideation; previous diagnosis of an organic mental disorder, schizophrenia, or any psychotic disorder; or psychiatric inpatient at any time during the last 5 years (if patients are excluded on the basis of depression scores indicating severe depression or suicidal ideation, referral for psychological services will be offered)
• Post-traumatic stress disorder (PTSD) greater than the 30% VA disability assignment (patients with less severe PTSD will be encouraged to participate)
• Existing meditation practice
• Weight more than 400 pounds