Pulse Pressure During Exercise Predicts Severe CAD

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Pulse Pressure During Exercise Predicts Severe
CAD

• Vinod Kannarkat, MD
• September 25, 2006

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Background

• Traditional stress test parameters include
• Exercise duration, ST segement change, Peak
  Systolic Blood Pressure
• ST segment depression gt 1mm
• 77.1 sensitive and 66.7 specific for CAD
• Does not predict severity

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Background

• SBP expected to rise 5 to 10 mm Hg per Metabolic
  Equivalent ( MET) 1 MET equivalent to energy
  expended in resting state.
• SBP rise at least 40 -50 mm Hg during peak
  exercise- return to baseline SBP expected 5 min
  post excercise

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Background

• Diastolic blood pressure should remain same or
  decrease during exercise.
• Greater than 10 mmHg increase in diastolic BP
  indicator of CAD
• We hypothesized that Pulse Pressure (SBP- DBP)
  would be a better predictor of CAD

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Methods

• Assessed exercise parameters and angiographic
  findings in pt who had positive stress test and
  subsequent angiography
• Retrospective study
• 1198 males( 58), 65 females (48) at VA

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Methods

• Severe CAD defined as stenosis
• 1) 50 or greater in left main
• 2) 70 or greater in 2 vessels with involvement
  of proximal LAD
• 3) 70 or greater in 3 vessels

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Results

• 78( 6.2) pt had severe CAD 64 of which had a PP
  lt 60
• PP lt 60 has 7-fold increase in the likelihood of
  having severe CAD
• Inverse relationship noted between pulse pressure
  and CAD severity

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Results

• Risk of CAD was reduced by 23 for every 5 mm Hg
  increase in PP gt 60
• Compared to SBP, duration of exercise, heart rate
  recovery- PP was the strongest predictor of
  severe CAD

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Conclusion

• Insufficient rise in PP at submaximal exercise is
  clinically useful marker of CAD
• PP particularly useful when pt asymptomatic
  during stress test and has baseline ST segment
  abnormalities
• PP predicts severity of disease where as ST
  segment depression is of limited value in this
  assessment

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Limitations

• Retrospective
• Sample size relatively small compared to projects
  of similar nature
• Few female subjects