title: The effect of caffeine on exercise tolerance and left ventricular function in patients with coronary artery disease.
abstract: OBJECTIVE
  To determine whether acute oral caffeine ingestion by patients with coronary artery disease results in decreased treadmill exercise performance or deterioration of echocardiographic measures of systolic or diastolic left ventricular function.
  
  
  METHODS
  Randomized, double-blind, placebo-controlled trial.
  
  
  METHODS
  Referral-based cardiovascular exercise laboratory at an urban teaching hospital.
  
  
  METHODS
  Thirteen volunteers with clinically stable coronary artery disease who had exercise tests after a 2-week caffeine-free washout period. Patients continued treatment with standard antianginal medications during the study period.
  
  
  METHODS
  Maximal exercise treadmill testing and exercise echocardiography were done at baseline, after acute ingestion of a placebo beverage (97% caffeine-free coffee), or after drinking an identical beverage containing 250 mg of caffeine sodium benzoate.
  
  
  RESULTS
  Acute ingestion of caffeine produced a serum level of 4.50 +/- 0.16 micrograms/mL, but had no effect on resting supine heart rate, blood pressure, left ventricular fractional shortening, posterior left ventricular wall thinning or peak rates of increase in left ventricular diastolic dimension. Despite a small increase in peak systolic blood pressure during exercise (baseline, 153 +/- 8; placebo, 154 +/- 8; caffeine, 161 +/- 7 mm Hg; P less than 0.05), exercise duration, time to onset of angina, and time to 0.1 mV ST depression did not differ after ingestion of placebo or caffeine. Rate-pressure product at onset of angina and onset of 0.1 mV of ST depression were also unchanged. In response to exercise, echocardiographic measures of left ventricular systolic and diastolic function were unchanged after caffeine compared with placebo ingestion.
  
  
  CONCLUSIONS
  These data suggest that patients with exercise-induced ischemia who are receiving appropriate antianginal therapy tolerate the caffeine-equivalent of three cups of coffee without detrimental effect on intensity of ischemia, myocardial function, or exercise duration.
authors.affiliation: Charles A. Dana Research Institute, Boston, Massachusetts.
authors.forename: A T
authors.initials: AT
authors.lastname: Hirsch
authors.forename: E V
authors.initials: EV
authors.lastname: Gervino
authors.forename: S
authors.initials: S
authors.lastname: Nakao
authors.forename: P C
authors.initials: PC
authors.lastname: Come
authors.forename: K J
authors.initials: KJ
authors.lastname: Silverman
authors.forename: W
authors.initials: W
authors.lastname: Grossman
mesh_terms: D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000503:physiopathology; D002110:Caffeine / Q000009:adverse effects* / Q000097:blood; D003327:Coronary Disease / Q000503:physiopathology*; D004311:Double-Blind Method; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects*; D005082:Physical Exertion / Q000187:drug effects*; D011897:Random Allocation
chemical_list: D002110:Caffeine