Cardiovascular mortality prediction in veterans with arm exercise vs pharmacologic myocardial perfusion imaging.

BACKGROUND: No data exist comparing outcome prediction from arm exercise vs pharmacologic myocardial perfusion imaging (MPI) stress test variables in patients unable to perform treadmill exercise. METHODS: In this retrospective study, 2,173 consecutive lower extremity disabled veterans aged 65.4 ± 11.0years (mean ± SD) underwent either pharmacologic MPI (1730 patients) or arm exercise stress tests (443 patients) with MPI (n = 253) or electrocardiography alone (n = 190) between 1997 and 2002. Cox multivariate regression models and reclassification analysis by integrated discrimination improvement (IDI) were used to characterize stress test and MPI predictors of cardiovascular mortality at ≥10-year follow-up after inclusion of significant demographic, clinical, and other variables. RESULTS: Cardiovascular death occurred in 561 pharmacologic MPI and 102 arm exercise participants. Multivariate-adjusted cardiovascular mortality was predicted by arm exercise resting metabolic equivalents (hazard ratio [HR] 0.52, 95% CI 0.39-0.69, P < .001), 1-minute heart rate recovery (HR 0.61, 95% CI 0.44-0.86, P < .001), and pharmacologic and arm exercise delta (peak-rest) heart rate (both P < .001). Only an abnormal arm exercise MPI prognosticated cardiovascular death by multivariate Cox analysis (HR 1.98, 95% CI 1.04-3.77, P < .05). Arm exercise MPI defect number, type, and size provided IDI over covariates for prediction of cardiovascular mortality (IDI = 0.074-0.097). Only pharmacologic defect size prognosticated cardiovascular mortality (IDI = 0.022). CONCLUSIONS: Arm exercise capacity, heart rate recovery, and pharmacologic and arm exercise heart rate responses are robust predictors of cardiovascular mortality. Arm exercise MPI results are equivalent and possibly superior to pharmacologic MPI for cardiovascular mortality prediction in patients unable to perform treadmill exercise.

Arm exercise as an alternative to pharmacologic stress testing: arm exercise stress testing and outcome.

BACKGROUND: Treadmill exercise variables are powerful predictors of all-cause mortality but are unobtainable in at least 50% of patients because of disabilities precluding lower extremity exercise. Arm exercise stress testing is a potentially cost-effective alternative, but no long-term outcome data are available. METHODS: We performed arm ergometer stress tests on 446 veterans aged 64.0 (11.1) years (mean [SD]) between 1997 and 2002 and investigated whether arm exercise capacity in resting metabolic equivalents, heart rate recovery (in beats per minute), delta (peak resting) heart rate (in beats per minute), and other exercise variables predict long-term all-cause mortality, myocardial infarction (MI), or coronary revascularization. RESULTS: During follow-up of 12.0 (1.3) years, 255 patients died (57.2%), 70 had MI (15.7%), and 118 underwent coronary revascularization (26.4%). After adjustment for significant demographic and clinical variables, death was predicted by arm metabolic equivalents (hazard ratio/SD 0.59, 95% CI 0.46-0.75, P < .001), heart rate recovery (hazard ratio/SD 0.64, 95% CI 0.49-0.83, P < .001), and delta heart rate (hazard ratio/SD 0.75, 95% CI 0.63-0.91, P < .001). No exercise variables prognosticated MI, but coronary revascularization was predicted by stress-induced ST-segment deviations (hazard ratio 2.64, 95% CI 1.16-4.33, P < .001), limiting angina (hazard ratio 4.70, 95% CI 1.81-12.22, P < .001), and an abnormal perfusion imaging result (hazard ratio 2.0, 95% CI 1.14-3.51, P < .02). CONCLUSIONS: Arm exercise capacity, heart rate recovery, and delta heart rate predict 12-year all-cause mortality and arm exercise-induced ST changes, limiting angina, and an abnormal nuclear imaging result portend coronary revascularization in lower extremity disabled veterans.

Arm exercise testing predicts clinical outcome.

BACKGROUND: Treadmill exercise testing provides prognostic and clinical information that is not available for patients with lower extremity disabilities who undergo pharmacologic stress tests. We sought to determine whether arm ergometer (AXT) exercise capacity in resting metabolic equivalents (METs) and hemodynamic and electrocardiographic responses to AXT are predictors of survival, myocardial infarction (MI), or coronary revascularization, individually or as a composite. METHODS: A prospective cohort of 359 veterans aged 63 +/- 11 (SD) years, who were unable or unwilling to perform treadmill exercise, underwent AXT stress testing for clinical reasons between 1997 and 2002 and were followed for 63 +/- 24 months to an end point of death or December 31, 2006. Average annual mortality, MI, revascularization, and combined event rates were 5.2%, 1.7%, 2.2%, and 7.1%, respectively. RESULTS: By univariate analysis, AXT METs were highly predictive of survival (P < .01; hazard ratio 0.58, 95% confidence interval 0.46-0.70). A greater delta (peak-rest) heart rate, peak exercise systolic blood pressure, and rate pressure product were associated with survival and event-free outcome (all P < .02). A positive exercise electrocardiogram was predictive of death, revascularization, and combined events (all P < .01), and borderline predictive of MI (P = .058). By Wald chi(2) analysis, age, clinical variables, exercise capacity in METs, a positive exercise electrocardiogram, and delta heart rate all had statistically significant incremental prognostic value (P < .05) for survival. CONCLUSION: In older veterans with lower extremity disabilities and more comorbidities than most study populations, arm exercise capacity, delta heart rate, and a positive electrocardiogram were independently predictive of survival and/or adverse cardiovascular outcomes.

A prognostic scoring system for arm exercise stress testing.

OBJECTIVE: Arm exercise stress testing may be an equivalent or better predictor of mortality outcome than pharmacological stress imaging for the ≥50% for patients unable to perform leg exercise. Thus, our objective was to develop an arm exercise ECG stress test scoring system, analogous to the Duke Treadmill Score, for predicting outcome in these individuals. METHODS: In this retrospective observational cohort study, arm exercise ECG stress tests were performed in 443 consecutive veterans aged 64.1 (11.1) years. (mean (SD)) between 1997 and 2002. From multivariate Cox models, arm exercise scores were developed for prediction of 5-year and 12-year all-cause and cardiovascular mortality and 5-year cardiovascular mortality or myocardial infarction (MI). RESULTS: Arm exercise capacity in resting metabolic equivalents (METs), 1 min heart rate recovery (HRR) and ST segment depression ≥1 mm were the stress test variables independently associated with all-cause and cardiovascular mortality by step-wise Cox analysis (all p<0.01). A score based on the relation HRR (bpm)+7.3×METs-10.5×ST depression (0=no; 1=yes) prognosticated 5-year cardiovascular mortality with a C-statistic of 0.81 before and 0.88 after adjustment for significant demographic and clinical covariates. Arm exercise scores for the other outcome end points yielded C-statistic values of 0.77-0.79 before and 0.82-0.86 after adjustment for significant covariates versus 0.64-0.72 for best fit pharmacological myocardial perfusion imaging models in a cohort of 1730 veterans who were evaluated over the same time period. CONCLUSIONS: Arm exercise scores, analogous to the Duke Treadmill Score, have good power for prediction of mortality or MI in patients who cannot perform leg exercise.

The Relation of Arm Exercise Peak Heart Rate to Stress Test Results and Outcome.

PURPOSE: Arm exercise is an alternative to pharmacologic stress testing for >50% of patients unable to perform treadmill exercise, but no data exist regarding the effect of attained peak arm exercise heart rate on test sensitivity. Thus, the purpose of this investigation was to characterize the relationship of peak arm exercise heart rate responses to abnormal stress test findings, coronary revascularization, and mortality in patients unable to perform leg exercise. METHODS: From 1997 until 2002, arm cycle ergometer stress tests were performed in 443 consecutive veterans age 64.1 yr (11.0 yr) (mean (SD)), of whom 253 also underwent myocardial perfusion imaging (MPI). Patients were categorized by frequency distributions of quartiles of percentage age-predicted peak heart rate (APPHR), heart rate reserve (HRR), and peak heart rate-systolic blood pressure product (PRPP). Exercise-induced ST-segment depression, abnormal MPI findings, coronary revascularization, and 12.0-yr (1.3 yr) Kaplan-Meier all-cause and cardiovascular mortality plots were then characterized by quartiles of APPHR, HRR, and PRPP. RESULTS: A reduced frequency of abnormal arm exercise ECG results was associated only with the lowest quartile of APPHR (≤69%) and HRR (≤43%), whereas higher frequency of abnormal MPI findings exhibited an inverse relationship trend with lower APPHR (P = 0.10) and HRR (P = 0.12). There was a strong inverse association of APPHR, HRR, and PRPP with all-cause (all P ≤ 0.01) and cardiovascular (P < 0.05) mortality. The frequency of coronary revascularization was unrelated to APPHR or HRR. CONCLUSIONS: Arm exercise ECG stress test sensitivity is only reduced at ≤69% APPHR or ≤43% HRR, whereas arm exercise MPI sensitivity and referral for coronary revascularization after arm exercise stress testing are not adversely affected by even a severely blunted peak heart rate. However, both all-cause mortality and cardiovascular mortality are strongly and inversely related to APPHR and HRR.

Arm exercise myocardial perfusion imaging for prognostication of long-term outcome.

INTRODUCTION: Pharmacologic evaluations constitute ≥50% of imaging stress tests, but exercise reduces adverse effects, improves myocardial perfusion imaging (MPI) quality and diagnostic results, and provides powerful prognostic and clinically important information on exercise capacity and cardiovascular responses to the relevant physiologic stress of exercise. Thus, our purpose was to determine whether arm exercise and MPI variables predict long-term outcome in patients who cannot perform leg exercise. METHODS: We performed arm exercise MPI stress tests in 253 consecutive patients age 64.5 (10.7) yr (mean (SD)) from 1997 to 2002 and investigated associations of arm exercise and abnormal MPI variables with all-cause mortality, myocardial infarction (MI), coronary artery bypass grafting (CABG), and percutaneous coronary intervention (PCI) during follow-up of 12.0 (1.3) yr. RESULTS: There were 156 deaths (61.7%), 47 patients suffered MI (18.6%), 24 underwent CABG (9.5%), and 50 had PCI (19.8%). Arm exercise capacity and delta HR (peak - resting) were strongly associated with survival after adjustment for significant demographic and clinical variables (Cox multivariate P < 0.0001 and 0.001, respectively). MPI was abnormal in 157 patients (62.1%). An abnormal arm exercise MPI was borderline predictive of mortality by Cox analysis (71.8% vs 46.4% for normal study; univariate P < 0.0001; multivariate P = 0.07) but resulted in 58% relative incremental integrated discrimination improvement over clinical variables for predicting death. Perfusion defect size also strongly predicted mortality (Cox multivariate P = 0.003). An abnormal arm exercise MPI study, perfusion defect type, and size all prognosticated PCI (all P ≤ 0.03) but not MI or CABG. CONCLUSIONS: Arm exercise MPI is a valuable approach for outcome prediction in patients unable to perform leg exercise.

Arm exercise stress perfusion imaging predicts clinical outcome.

Treadmill exercise capacity in resting metabolic equivalents (METs) and stress hemodynamic, electrocardiographic (ECG), and myocardial perfusion imaging (MPI) responses are independently predictive of adverse clinical events. However, limited data exist for arm ergometer stress testing (AXT) in patients who cannot perform leg exercise because of lower extremity disabilities. We sought to determine the extent to which AXT METs, hemodynamic, ECG, and MPI responses to arm exercise add independent incremental value to demographic and clinical variables for prediction of all-cause mortality, myocardial infarction (MI), or late coronary revascularization, individually or as a composite. A prospective cohort of 186 patients aged 64 ± 10 (SD) yr, unable to perform lower extremity exercise, underwent AXT MPI for clinical reasons between 1997 and 2002, and were followed for 62 ± 23 mo, to an endpoint of death or 12/31/2006. Average annual rates were 5.4% for mortality, 2.2% for MI, 2.5% for late coronary revascularization, and 8.0% for combined events. After adjustment for age and clinical variables, AXT METs [P < 0.05; hazard ratio (HR) = 0.59; confidence interval (CI) = 0.35-0.84] and abnormal MPI (P < 0.01; HR = 2.48; CI = 2.15-2.81) were independently predictive of mortality. A positive AXT ECG (P < 0.05; HR = 2.61; CI = 2.13-3.10) was predictive of MI. Death and MI combined were prognosticated by METs (P < 0.05; HR = 0.63; CI = 0.41-0.85), MPI (P < 0.05; HR = 1.77; CI = 1.49-2.05), and a positive AXT ECG (P < 0.05; HR = 1.86; CI = 1.55-2.17). In conclusion, for high risk older patients who cannot perform leg exercise because of lower extremity disabilities, AXT METs are as important as MPI for prediction of mortality alone and death and MI combined, and a positive AXT ECG prognosticates MI alone and death and MI combined.