Clinical role of the Duke Activity Status Index in the selection of the optimal type of stress myocardial perfusion imaging study in patients with known or suspected ischemic heart disease

Pilot study to evaluate the safety and effectiveness of etidronate treatment for arterial calcification due to deficiency of CD73 (ACDC)

BACKGROUND

Arterial calcification due to deficiency of CD73 (ACDC; OMIM 211800) is a rare genetic disease resulting in calcium deposits in arteries and small joints causing claudication, resting pain, severe joint pain, and deformities. Currently, there are no standard treatments for ACDC. Our previous work identified etidronate as a potential targeted ACDC treatment, using in vitro and in vivo disease models with patient-derived cells. In this study, we test the safety and effectiveness of etidronate in attenuating the progression of lower-extremity arterial calcification and vascular blood flow based on the computed tomography (CT) calcium score and ankle-brachial index (ABI).

METHODS

Seven adult patients with a confirmed genetic diagnosis of ACDC were enrolled in an open-label, nonrandomized, single-arm pilot study for etidronate treatment. They took etidronate daily for 14 days every 3 months and were examined at the NIH Clinical Center bi-annually for 3 years. They received a baseline evaluation as well as yearly follow up after treatment. Study visits included imaging studies, exercise tolerance tests with ABIs, clinical blood and urine testing, and full dental exams.

RESULTS

Etidronate treatment appeared to have slowed the progression of further vascular calcification in lower extremities as measured by CT but did not have an effect in reversing vascular and/or periarticular joint calcifications in our small ACDC cohort.

CONCLUSIONS

Etidronate was found to be safe and well tolerated by our patients and, despite the small sample size, appeared to show an effect in slowing the progression of calcification in our ACDC patient cohort.(ClinicalTrials.gov Identifier NCT01585402).

Aortic pulse wave analysis and functional capacity of heart transplantation candidates: a pilot study

We compared cardiovascular parameters obtained with the Mobil-O-Graph and functional capacity assessed by the Duke Activity Status Index (DASI) before and after Heart Transplantation (HT) and also compared the cardiovascular parameters and the functional capacity of candidates for HT with a control group. Peripheral and central vascular pressures increased after surgery. Similar results were observed in cardiac output and pulse wave velocity. The significant increase in left ventricular ejection fraction (LVEF) postoperatively was not followed by an increase in the functional capacity. 24 candidates for HT and 24 controls were also compared. Functional capacity was significantly lower in the HT candidates compared to controls. Stroke volume, systolic, diastolic, and pulse pressure measured peripherally and centrally were lower in the HT candidates when compared to controls. Despite the significant increase in peripheral and central blood pressures after surgery, the patients were normotensive. The 143.85% increase in LVEF in the postoperative period was not able to positively affect functional capacity. Furthermore, the lower values of LVEF, systolic volume, central and peripheral arterial pressures in the candidates for HT are consistent with the characteristics signs of advanced heart failure, negatively impacting functional capacity, as observed by the lower DASI score.

Usefulness of the Duke Activity Status Index to Assess Exercise Capacity and Predict Risk Stratification in Patients with Pulmonary Arterial Hypertension

Exercise capacity is an important component of risk assessment for pulmonary arterial hypertension (PAH). We investigated the association of the Duke Activity Status Index (DASI) with peak oxygen consumption (peakVO₂) and explored whether the DASI can discriminate the high-risk individuals in patients with PAH, according to peakVO₂ < 11 mL/min/kg. A total of 89 patients were evaluated using cardiopulmonary exercise testing (CPET) and DASI. The correlation between the DASI and peakVO₂ was measured by univariate analysis, and a receiver operating characteristic (ROC) curve analysis was conducted. The DASI was correlated with peakVO₂ in the univariate analysis. The ROC curve analysis revealed that the DASI had a discriminative value for identifying the individuals with a high risk in PAH patients (p < 0.001), with an area under ROC curve (AUC) of 0.79 (95% CI: 0.67-0.92). Similar results were observed in patients with PAH associated with congenital heart disease (CHD-PAH), (p = 0.001), with an AUC of 0.80 (95% CI: 0.658-0.947). Therefore, DASI reflects exercise capacity in patients with PAH and has good ability to discriminate patients with a low risk and a high risk, and it may be included in the risk assessment of PAH.

Elaboration of a French version of the Duke Activity Status Index questionnaire and performance to predict functional capacity

BACKGROUND

Guidelines recommend detecting poor functional capacity (VO_2max < 14 ml.kg^-1.min^-1) to assess preoperative cardiac risk. This screening is performed via a cardiopulmonary exercise test (CPET), the self-reported inability to climb two flights of stairs, or the use of the Duke Activity Status Index (DASI) questionnaire, which has shown a significant correlation with VO_2max and postoperative outcomes. The objectives of the present study were: 1) to create a French version of the DASI questionnaire (FDASI); 2) to assess its diagnostic performance in predicting functional capacity.

METHODS

Consecutive adult patients undergoing CPET for medical or preoperative evaluation were prospectively included between May 2020 and March 2021. All patients were asked to complete FDASI as a self-questionnaire and report their inability to climb two flights of stairs.

RESULTS

122 patients were included. Test-retest reliability was 0.88 and 23 (19%) patients experienced a VO_2max < 14 ml.kg^-1.min^-1. There was a significant positive relationship between FDASI and VO_2max: r² = 0.32; p <  0.001. ROC_AUC was 0.81 [95%CI: 0.73-0.89]. The best FDASI score threshold was 36 points, leading to sensitivity and specificity values of 87% [74-100] and 68% [56-79], respectively. Besides, sensitivity and specificity were 35% [17-56] and 92% [86-97] for the self-reported inability to climb two flights of stairs.

CONCLUSION

A FDASI score of 36 represents a reliable threshold the clinicians could routinely use to identify patients with a VO_2max < 14 ml.kg^-1.min^-1. FDASI could advantageously replace the self-reported inability to climb two flights of stairs.

Safety and efficacy of RT234 vardenafil inhalation powder on exercise parameters in pulmonary arterial hypertension: phase II, dose-escalation study design

BACKGROUND

Pulmonary arterial hypertension (PAH) is a progressive disease characterized by high mean pulmonary arterial pressure (≥ 20 mmHg) and remodeling of the vascular arteries. Approved therapies improve symptoms and delay clinical worsening in the long term, but they do not relieve acute exertional symptoms. RT234, a drug/device combination (Respira Therapeutics, Palo Alto, CA, USA) that delivers the phosphodiesterase 5 inhibitor vardenafil to the lungs via inhalation, has been shown to reduce pulmonary vascular resistance in patients with PAH. This study aims to evaluate whether RT234 can increase oxygen capacity during cardiopulmonary exercise testing (CPET) in patients with PAH.

METHODS

This prospective, multi-center, open-label, two-cohort, dose-escalation, phase IIb trial in patients with PAH will evaluate the safety and efficacy of RT234 in improving exercise parameters. The trial began in September 2020 and is expected to be completed by early 2024. Patients eligible for enrollment will have a right heart catheterization-confirmed diagnosis of PAH, a 6-minute walking distance of ≥ 150 m, a minute ventilation/carbon dioxide production slope of ≥ 36, and will be on up to three stable oral and/or inhaled (not parenteral) PAH-specific background therapies. The estimated sample size is 86 patients, who will be divided into two dose cohorts. Cohort 1 will receive 0.5 mg RT234, and cohort 2 will receive 1.0 mg RT234. Each cohort will contain two subgroups based on the number of PAH background medications (up to two vs three). The trial will assess patients' changes from baseline in peak oxygen consumption (VO₂) during CPET 30 minutes after a single dose of 0.5 mg or 1.0 mg RT234, the change in the 6-minute walking distance, and the pharmacokinetics and safety profile of single doses of RT234.

CONCLUSION

This is the first trial involving an as-needed medication for PAH. The trial will provide insights into the safety and efficacy of as-needed RT234 in treating the acute symptoms of PAH during exercise and will inform the design of further trials.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier NCT04266197.

Usefulness of the Duke Activity Status Index to Select an Optimal Cardiovascular Exercise Stress Test Protocol

Exercise testing represents the preferred stress modality for individuals undergoing evaluation of suspected myocardial ischemia. Patients with limited functional status may be unable to achieve an adequate exercise stress, thus influencing the diagnostic sensitivity of the results. The Duke Activity Status Index (DASI) is a clinically applicable tool to estimate exercise capacity. The purpose of the current study was to assess the utility of the DASI to identify patients unable to achieve an adequate exercise stress result. Patients referred for exercise stress testing were administered the DASI pre-exercise. Baseline characteristics and exercise variables were evaluated including DASI-metabolic equivalents (DASI-METs), peak METs, exercise time (ET), and %-predicted maximal heart rate (%PMHR). Criteria for determining adequate exercise stress was defined as ≥85%PMHR or ≥ 5-METs at peak exercise. In 608 cardiovascular stress tests performed during the study period; 314 were exercise stress. The median DASI-METs (8.4 [interquartile range; 6.7 to 9.9]) was associated with estimated peak exercise METs (R=0.50, p <0.001), ET (R=0.29, p <0.001), and %PMHR (R=0.19, p = 0.003). DASI-METs were different between those with < or ≥85%PMHR (7.9 [6.6-9.0] vs. 8.9 [7.1-9.9], P=0.025) and those with < or ≥5-METs (5.8 [4.6 to 6.6] versus 8.9 [7.3-9.9], p <0.001). Receiver operating characteristic curve analysis identified a DASI-MET threshold of ≤/>7.4 to optimally predict adequate exercise stress (sensitivity=93%, specificity=71%). In conclusion, the DASI correlates with peak METs, ET, and %PMHR among patients referred for exercise testing and can be used to identify patients with an increased likelihood of an inadequate stress test result.

Does Duke Activity Status Index help predicting functional exercise capacity and long-term prognosis in patients with pulmonary hypertension?

BACKGROUND

To investigate the association of Duke Activity Status Index (DASI) with 6-minute walk test (6MWT) and WHO-Functional Class (WHO-FC) in patients with pulmonary hypertension (PH), as well as exploring whether DASI can discriminate between the patients with better and worse long-term prognosis according to 400 m cut-off score in 6MWT.

METHODS

Eighty-five medically stable PH patients who met eligibility criteria were included. All patients were evaluated using 6MWT and DASI. The prognostic utility of the DASI was assessed using univariate linear regression and receiver operating characteristic (ROC) curve analysis.

RESULTS

The DASI was an independent predictor for both 6MWT and WHO-FC, explaining 50% of variance in 6MWT and 30% of variance in WHO-FC class (p < 0.001). In addition, DASI significantly correlated to 6MWT (r = 0.702) and WHO-FC class (r = 0.547). The ROC curve analysis revealed that the DASI had a discriminative value for identifying the patients with better long-term prognosis (p < 0.001), with an area under ROC curve of 0.867 [95% CI = 0.782-0.952]. The DASI ≥26 was the optimal cut-off value for better long-term prognosis, having sensitivity of 0.74 and a specificity of 0.88.

CONCLUSIONS

The DASI is a valid tool reflecting functional exercise capacity in patients with PH. Considering its ability to discriminate between the patients with better or worse long-term prognosis, it may help identifying the patients at higher risk.

Myocardial perfusion imaging and appropriateness of the test for preoperative cardiac risk evaluation in an Iranian population: clinical role of Duke Activity Status Index

OBJECTIVE

For preoperative radionuclide myocardial perfusion imaging, metabolic equivalent is one of the key factors to evaluate the appropriateness. Duke Activity Status Index is a practical method to calculate metabolic equivalents. We intended to validate Duke Activity Status Index in our population for the assessment of preoperative myocardial perfusion imaging appropriateness.

METHODS

A total of 542 patients referred for myocardial perfusion imaging were recruited. A questionary compiled from Duke Activity Status Index was filled out based on which metabolic equivalents were calculated. Demographic data and history of cardiac risk factors were also collected. Myocardial perfusion imaging was performed using a 2-day stress-rest protocol either by exercise tolerance test or by pharmacologic stress through injection of Tc-MIBI and imaging by a dual-head gamma camera.

RESULTS

Out of 542 patients, 369 (68.1%) were evaluated for preoperative risk assessment. Metabolic equivalents (oxygen consumption/min/kg) were calculated at 9.3 ± 5.1, 10.8 ± 4.8, and 8.7 ± 5.1 in total, preoperative patients and patients evaluated for ischemia due to nonsurgical purposes, respectively (p = 0.001). The myocardial perfusion imaging was rarely appropriate in 291 (79.5%), maybe appropriate in 67 (18.3%), and appropriate in 8 (2.2%) patients. The prevalence of abnormal myocardial perfusion imaging was 22.5%, 28.4%, and 12.5% in "rarely appropriate," "maybe appropriate," and "appropriate" scenarios, respectively. Metabolic equivalents were similar between patients with normal and abnormal myocardial perfusion imaging (8.7 ± 5.0 vs. 8.5 ± 5.4).

CONCLUSION

Either Duke Activity Status Index is not a proper tool for calculation of metabolic equivalents or the appropriate use criteria is not operational in the population of Iranian preoperative patients in which cultural factors may contribute.

Duke Activity Status Index cut-off scores for assessing functional capacity after stroke

PURPOSE

To determine the Duke Activity Status Index (DASI) cut-off scores and verify if they would be able to discriminate between chronic stroke individuals, who had poor, from those who had good functional capacity (FC).

MATERIALS AND METHODS

Cross-sectional study, where 92 individuals with chronic stroke had their FC measured by DASI scores and were classified into community and non-community walkers. Both the receiver operating characteristic and the area under the curve were used to determine the best DASI cut-off values that could discriminate between individuals, who had poor, from those who had good FC. Binary logistic regression analysis is used to investigate the ability of DASI scores in predicting community walkers.

RESULTS

DASI cut-off value of 31.95 showed to be sensitive and specific to differentiate between individuals, who had poor from good FC. The regression analysis revealed that the chance of individuals, who had better FC (≥ 31.95) be community walkers was 10.69 (95%CI:4-32.75) times higher than that of those who had poor FC (< 31.95). The model demonstrated good predictive ability.

CONCLUSIONS

The DASI cut-off value of 31.95 showed to be sensitive and specific to distinguish between chronic stroke individuals, who had poor, from those who had good FC.IMPLICATIONS FOR REHABILITATIONThe identification of individuals, who have good and poor functional capacity, is important for clinical reasoning and decision-making in stroke rehabilitation.The Duke Activity Status Index (DASI) is a clinically useful tool for the assessment of functional capacity, based upon the performance of common daily living activities.The DASI cut-off of 31.95 points was able to discriminate between individuals with stroke, who had poor, from those who had good functional capacity.The chance of individuals, who had good functional capacity (DASI ≥ 31.95) be community walkers was 10.69 times higher than that of those who had poor functional capacity (DASI < 31.95).The findings support the use of the DASI as a simple tool for the assessment of functional capacity, especially in low-resource settings.

Comparative efficiency of exercise stress testing with and without stress-only myocardial perfusion imaging in patients with low-risk chest pain

OBJECTIVES

To compare major adverse cardiac event (MACE), downstream resource utilization, and direct cost of care for low-risk chest pain patients observed in the clinical decision unit (CDU) with exercise treadmill testing (ETT) and with stress-only myocardial perfusion imaging (sMPI).

BACKGROUND

CDUs are poised to increase efficiency and resource utilization. However, the optimal testing strategy that would assure favorable outcomes while decreasing cost is not defined.

METHODS

1016 subjects from 2 locations were propensity score-matched (PSM) by age, gender, pre-test likelihood, Duke treadmill score, and test results. Outcomes were length of stay >24 hours, MACE (acute coronary syndrome, revascularization, cardiac death), downstream resource use (admission for chest pain, repeat testing, angiography), and mean direct cost per patient.

RESULTS

PSM yielded 680 patients (340 matches). 98% of all tests were normal. 96.6% of patients were discharged from the CDU within 24 hours but twice as many exceeded 24 hours in the sMPI group. There were no cardiac deaths. MACE rate was 1.47% at 72 hours and 1% at 1 year. Downstream resource use was 4.82% at 72 hours, and 7.69% at 1 year. The sMPI group was event-free longer than the ETT group reflecting less repeat testing. The mean direct cost was 30% higher for sMPI ($3168.70) vs. ETT ($2226.96).

CONCLUSION

Low-risk chest pain patients in the observation unit had low MACE rate, not different for ETT vs. sMPI. The majority of ETT and sMPI tests were normal. The sMPI reduced additional testing, but resulted in greater expense and longer stay.

Electronically self-assessed functional capacity and exercise testing: A comparison of the Duke Activity Status Index and Patient-Reported Outcomes Measurement Information System tools

PURPOSE

Electronic screening tools, such as Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function Short-Form 12a (PF-SF12a), may aid in the assessment of functional capacity. However, PROMIS PF-SF12a has not been validated against exercise capacity, or compared with established questionnaires, including the Duke Activity Status Index (DASI). We compared the DASI and PROMIS PF-SF12a to the maximum metabolic equivalents (METs) achieved during exercise stress testing.

METHODS

DASI and PROMIS PF-SF12a were electronically administered to 100 adult patients (median age 56years, 61% male) immediately before exercise stress testing. DASI-predicted METs and PROMIS T score were calculated. Correlations with exercise METs with and without age adjustment were examined. Linear regression lines were derived and adjusted r² statistic was calculated. We compared models with the Davidson-Mackinnon J test.

RESULTS

The median (interquartile range) DASI-predicted METs, PROMIS Tscore, and exercise METs were 8.97 (7.61-9.89), 47.90 (43.33-52.40), and 10.10 (10.10-12.80), respectively. In unadjusted correlation analyses, PROMIS accounted for 26% of the variance in exercise METs compared with 38% with DASI. With age adjustment, the r²values increased to 0.36 (PROMIS) and 0.46 (DASI). In both unadjusted and age-adjusted analyses, inclusion of DASI improved prediction of exercise METs beyond PROMIS T score (P<.0001). In contrast, PROMIS T score did not improve exercise MET prediction compared with DASI alone (P>.10).

CONCLUSION

Among patients undergoing clinically indicated exercise stress testing, DASI outperformed PROMIS PF-SF12a as a predictor of exercise METs.

Validation of the Thai version of the Duke Activity Status Index in patients with a previous myocardial infarction

Background: The Duke Activity Status Index is a widely used instrument for measuring functional status in patients with cardiovascular disease. However, items and subscales on this instrument have not been validated for Thai patients with a previous myocardial infarction (MI).

Objective: To test the reliability and validity of the Thai version of the Duke Activity Status Index (DASI-T) in Thai patients with a previous MI using a cross-sectional study design.

Methods: The DASI-T was translated using forward and backward translation methods and administered to 100 MI patients from outpatient departments of two general hospitals in Thailand. Internal consistency was determined to test reliability. Two criterion measures (i.e. Canadian Cardiovascular Society (CCS) classification, SF-36 physical functioning subscale) were used to test the concurrent validity of the DASI-T. Age group and CCS classification were used to determine known-groups validity of the DASI-T.

Results: Cronbach’s α for the DASI-T total score was 0.76. No ceiling or floor effect was detected for the DASI-T total score. DASI-T total score was significantly correlated with the CCS classification (r = -0.68, P < 0.01) and SF-36 physical functioning subscale (r = 0.79, P < 0.01). DASI-T total scores could differentiate MI patients based on age (P = 0.040) or CCS classification (P = 0.000).

Conclusion: The DASI-T is a potentially reliable and valid instrument with which to assess functional status in MI patients and is also useful to evaluate a treatment effect and be a guideline for clinical purposes (i.e. exercise prescription, risk stratification).

The role of treadmill exercise testing in women

Treadmill exercise electrocardiogram (ECG) is one of the most commonly used noninvasive tests for the assessment of ischemic heart disease (IHD). Sex-specific challenges in diagnostic and prognostic tests methods for IHD outlined the importance of pretest probability evaluation and referral bias using risk-prediction charts available for both asymptomatic and symptomatic women. Accordingly, exercise ECG has been indicated as the initial test for the symptomatic women at intermediate risk of IHD who has a normal resting ECG and is capable of maximal exercise. However, the difficulties of using exercise testing for diagnosing IHD in women have led to an initial speculation that stress imaging may be preferred to standard stress testing. This editorial analyzed a large body of evidence on the diagnostic and prognostic powers of treadmill ECG and exercise myocardial perfusion imaging (MPI) according to new advanced imaging technologies.

Relationships between self-reported and performance-based measures of functional capacity in individuals with chronic stroke

[Purpose] The aim of this study was to investigate the associations between self-reported and valid performance-based measures of functional capacity in individuals with chronic stroke. [Subjects and Methods] Self-reported measures of functional capacity of 31 individuals with chronic stroke were assessed by the Duke Activity Status Index scores, whereas performance-based measures were assessed by the distance covered (in meters) and oxygen consumption (relative oxygen consumption, in ml·kg⁻¹·min⁻¹) during the six-minute walking test. [Results] The subjects had a mean age of 58.6±13 years and a mean time since the onset of stroke of 28.3±15.1 months. They had a mean Duke Activity Status Index of 27.3±14.4, mean distance covered of 325.2±140.2 m, and mean relative oxygen consumption of 9.6±2.3 ml·kg⁻¹·min⁻¹. Significant, positive, and moderate to good correlation coefficients were found between the Duke Activity Status Index scores and the distance covered during the six-minute walking test (r=0.68). Significant, positive, and fair associations were also found between the Duke Activity Status Index scores and relative oxygen consumption values obtained during the six-minute walking test (r=0.45). [Conclusion] The findings of the present study support the clinical use of the Duke Activity Status Index as a tool to assist in clinical evaluations of functional capacity of individuals with chronic stroke.

Duke Activity Status Index for cardiovascular diseases: validation of the Portuguese translation

BACKGROUND

The Duke Activity Status Index (DASI) assesses the functional capacity of patients with cardiovascular disease (CVD), but there is no Portuguese version validated for CVD.

OBJECTIVES

To translate and adapt cross-culturally the DASI for the Portuguese-Brazil language, and to verify its psychometric properties in the assessment of functional capacity of patients with CVD.

METHODS

The DASI was translated into Portuguese, then checked by back-translation into English and evaluated by an expert committee. The pre-test version was first evaluated in 30 subjects. The psychometric properties and correlation with exercise testing was performed in a second group of 67 subjects. An exploratory factor analyses was performed in all 97 subjects to verify the construct validity of the DASI.

RESULTS

The intraclass correlation coefficient for test-retest reliability was 0.87 and for the inter-rater reliability was 0.84. Cronbach's α for internal consistency was 0.93. The concurrent validity was verified by significant positive correlations of DASI scores with the VO2max (r = 0.51, p < 0.001). The factor analysis yielded two factors, which explained 54% of the total variance, with factor 1 accounting for 40% of the variance. Application of the DASI required between one and three and a half minutes per patient.

CONCLUSIONS

The Brazilian version of the DASI appears to be a valid, reliable, fast and easy to administer tool to assess functional capacity among patients with CVD.

Psychometric testing of the Duke Activity Status Index in patients with heart failure

BACKGROUND

Patients with heart failure (HF) experience difficulty performing activities of daily living. As impaired functional status is adversely associated with outcomes, it is important to accurately evaluate patient functional status. The Duke Activity Status Index (DASI) is a 12-item, self-administered questionnaire to measure functional status. However, its psychometric properties have not been determined in patients with HF. The purpose of this study was to examine the psychometric properties of the DASI in patients with HF.

METHODS AND RESULTS

We used data from 297 patients with a diagnosis of HF (age 61±11 years, 31% female) for psychometric testing. Internal consistency reliability of the DASI was high (Cronbach's alpha=0.86). Criterion-related validity was supported by significantly different DASI scores for each New York Heart Association classification. Construct validity was supported by significant correlation of DASI scores with health-related quality of life (r = -0.64), depressive symptoms (r = -0.44), and N-terminal B-type natriuretic peptide (r = -0.14).

CONCLUSION

Our data support the psychometric properties of the DASI as a measure of functional status in patients with HF. This instrument can be used to evaluate functional status and enhance health care provider understanding of functional status related to daily living from the patient perspective.

A strategy of symptom-limited exercise with regadenoson-as-needed for stress myocardial perfusion imaging: a randomized controlled trial

BACKGROUND

Ambulatory patients with uncertain functional capacity may benefit from combined exercise and vasodilator stress protocols for myocardial perfusion imaging (MPI). The safety and MPI image quality with regadenoson administered during symptom-limited exercise have not been prospectively evaluated.

METHODS AND RESULTS

A total of 140 patients (mean age 61 years, 48% female) referred for exercise with vasodilator stress MPI were randomized 2:1 to a strategy of exercise with regadenoson-as-necessary (Ex-Reg, n = 96) or dipyridamole with exercise (Dip-Ex, n = 44) after Duke Activity Status Index (DASI) scoring (median score 28 vs 24, P = .09). Ex-Reg subjects commenced treadmill exercise and regadenoson was administered only if the subject was unable to reach standard endpoints. Dip-Ex subjects received dipyridamole prior to symptom-limited exercise. Hemodynamics were recorded throughout. Subjects completed symptom questionnaires and MPI image quality was assessed by blinded read. Ex-Reg subjects were more likely to achieve ≥85% age-predicted maximum heart rate than Dip-Ex subjects (57% vs 32%, P < .01). Only 50% of subjects meeting inclusion criteria and randomized to Ex-Reg required regadenoson and none had symptomatic hemodynamic changes. Severe side effects or adverse events occurred in 16% of Ex-Reg and 24% of Dip-Ex subjects (P = .12). MPI image quality was "good" or "excellent" in 88% of Ex-Reg subjects and 86% of Dip-Ex subjects (P = .33).

CONCLUSION

A strategy of exercise with regadenoson-as-needed for MPI offers similar safety and side effect profile with similar image quality compared to dipyridamole with exercise, with reduced pharmaceutical use.

Safety and feasibility of adjunctive regadenoson injection at peak exercise during exercise myocardial perfusion imaging: The Both Exercise and Regadenoson Stress Test (BERST) trial

BACKGROUND

The data existing in the literature regarding the safety of using regadenoson with symptom-limited exercise are limited, which motivated the authors to undertake this randomized study.

METHODS

We offered patients scheduled to undergo vasodilator stress nuclear myocardial perfusion imaging the opportunity to exercise instead. Patients who failed to reach target heart rate (THR) were randomized to (1) receive regadenoson at peak exercise or (2) stop exercise and receive regadenoson at rest. Patients who reached THR received a standard Tc-99m sestamibi injection with no regadenoson.

RESULTS

200 patients were included (66% male, mean age 52.5 ± 13.6). 125 patients (62%) reached THR with exercise alone. All stress protocols were well tolerated, and there were no significant adverse events. There were no statistically significant differences in the extent of perfusion abnormalities, image quality, or rate of referral to cardiac catheterization within 60 days between the groups. In fully adjusted logistic regression models, beta-blocker use and diabetes remained significant univariate predictors of failure to reach THR (OR 0.21, 95% CI 0.1-0.5, P < .0001, OR 0.34, 95% CI 0.2-0.7, P = .004, respectively).

CONCLUSIONS

A protocol combining regadenoson at peak exercise in patients unable to reach THR with exercise is feasible, well-tolerated, and yields comparable imaging results to a standard regadenoson injection at rest. In addition, pharmacologic stress testing may be over-ordered in current clinical practice, as patients referred for such testing were often able to exercise.

An Approach to Asymptomatic and Atypically or Typically Symptomatic Women with Cardiac Disease

The evaluation of women who are asymptomatic or presenting for evaluation of stable cardiac disease symptoms has been the focus of much research in the past decade. The rationale for this research has been that fatality rates for coronary heart disease remain higher for women than men. Detection of high-risk populations is a core component of targeted therapeutic risk reduction and is a valuable way to identify women who may benefit from early intervention that could result in improved clinical outcomes. This article discusses the evidence on assessment of women with and without suspected cardiac symptoms.