Value of reserve pulse pressure in improving the risk stratification of patients with normal myocardial perfusion imaging

Aims: To evaluate the incremental prognostic value of reserve-pulse pressure (reserve-PP: exercise-PP minus rest-PP) to standard risk factors among patients with suspected coronary artery disease (CAD) but normal exercise myocardial perfusion imaging (MPI).

Methods and results: We studied 4269 consecutive symptomatic patients without known CAD who were referred for exercise MPI but had normal MPI results (mean age 58 ± 12 years, 56% females, 84% referred for evaluation of chest pain or dyspnoea, 95% with intermediate pretest likelihood of CAD). There were 202 deaths over 5.1 ± 1.4 years of follow-up. Reserve-PP was abnormal (<44 mmHg increase in PP from rest) in 1894 patients (44%). Patients with an abnormal reserve-PP had a higher risk of death compared with patients with normal reserve-PP [hazard ratio (HR): 2.47, 95% CI, 1.8-3.3]. In multivariable models adjusting for age, sex, ejection fraction, medications, heart rate recovery, Duke treadmill score (DTS), and rest-PP, each 10 mmHg lower reserve-PP was associated with a 20.6% increase in risk-adjusted mortality (adjusted HR 0.83, 95% CI 0.76-0.91). Models incorporating reserve-PP significantly reclassified risk compared with models without these parameters (net reclassification index 14.3%, P = 0.0007; integrated discrimination index 0.69, P = 0.01).

Conclusion: In patients without a history of CAD and a normal MPI, an abnormal reserve-PP identified and reclassified those at higher risk of death independent of known risk factors and DTS.