Risk Stratification of Patients With Chest Pain of Unknown Origin
Risk Stratification of Patients With Chest Pain of Unknown Origin
Background Dual imaging stress echocardiography, combining the evaluation of wall motion and coronary flow reserve (CFR) on the left anterior descending artery (LAD), and computed tomography coronary angiography (CTCA) are established techniques for assessing prognosis in chest pain patients. In this study we compared the prognostic value of the two methods in a cohort of patients with chest pain having suspected coronary artery disease (CAD).
Methods A total of 131 patients (76 men; age 68 ± 9 years) with chest pain of unknown origin underwent dipyridamole (up to 0.84 mg/kg over 6 min) stress echo with CFR assessment of LAD by Doppler and CTCA. A CFR ≤ 1.9 was considered abnormal, while > 50% lumen diameter reduction was the criterion for significant CAD at CTCA.
Results Of 131 patients, 34 (26%) had ischemia at stress echo (new wall motion abnormalities), and 56 (43%) had reduced CFR on LAD. Significant coronary stenosis at CTCA was found in 69 (53%) patients. Forty-six patients (84%) with abnormal CFR on LAD showed significant CAD at CTCA (p < 0.001). Calcium score was higher in patients with reduced than in those with normal CFR (265 ± 404 vs 131 ± 336, p = 0.04). During a median follow-up of 7 months (1st to 3rd quartile: 5–13 months), there were 45 major cardiac events (4 deaths, 11 nonfatal myocardial infarctions, and 30 late [≥6 months] coronary revascularizations). At Cox analysis, independent prognostic indicators were calcium score > 100 (HR 2.84, 95% CI 1.33–6.07, p = 0.007), significant CAD at CTCA (HR 2.68, 95% CI 1.23–5.82, p = 0.013), and inducible ischemia or CFR <1.9R on LAD on dual imaging stress echo (HR 2.25, 95% CI 1.05–4.84, p = 0.038).
Conclusions Functional and anatomical evaluation using, respectively, dual imaging stress echocardiography and CTCA are both effective modalities to risk stratify patients with chest pain of unknown origin, yielding independent and comparable prognostic value. Compared to CTCA, however, stress echocardiography has the advantage of lower cost and of being free of radiations.
Dual imaging of wall motion and coronary flow reserve (CFR) in the left anterior descending coronary artery (LAD) is the current state-of-the-art technique for vasodilator stress echocardiography providing superior diagnostic and prognostic value compared to standard stress testing. In particular, a reduced CFR in the LAD added prognostic information over wall motion analysis in patients with known or suspected coronary artery disease (CAD). Interestingly, the prognostic capability of CFR was not affected by ongoing anti-ischemic therapy.
Computed tomography coronary angiography (CTCA) has emerged as a noninvasive effective diagnostic imaging modality, providing good correlation with invasive measurement of stenosis severity. In particular, CTCA demonstrated high accuracy and negative predictive value in patients referred for chest pain of unknown origin. Unfortunately, CTCA provides a non-negligible radiation exposure with associated cancer risk. In addition, it is unable to assess the hemodynamic meaning of vessel stenosis, as fewer than half of CTCA identified obstructive lesions confirmed by coronary angiography cause ischemia.
This prospective, observational study was aimed at assessing the prognostic value of dual imaging dipyridamole stress echocardiography and CTCA in a cohort of chest pain patients having suspected CAD.
Abstract and Introduction
Abstract
Background Dual imaging stress echocardiography, combining the evaluation of wall motion and coronary flow reserve (CFR) on the left anterior descending artery (LAD), and computed tomography coronary angiography (CTCA) are established techniques for assessing prognosis in chest pain patients. In this study we compared the prognostic value of the two methods in a cohort of patients with chest pain having suspected coronary artery disease (CAD).
Methods A total of 131 patients (76 men; age 68 ± 9 years) with chest pain of unknown origin underwent dipyridamole (up to 0.84 mg/kg over 6 min) stress echo with CFR assessment of LAD by Doppler and CTCA. A CFR ≤ 1.9 was considered abnormal, while > 50% lumen diameter reduction was the criterion for significant CAD at CTCA.
Results Of 131 patients, 34 (26%) had ischemia at stress echo (new wall motion abnormalities), and 56 (43%) had reduced CFR on LAD. Significant coronary stenosis at CTCA was found in 69 (53%) patients. Forty-six patients (84%) with abnormal CFR on LAD showed significant CAD at CTCA (p < 0.001). Calcium score was higher in patients with reduced than in those with normal CFR (265 ± 404 vs 131 ± 336, p = 0.04). During a median follow-up of 7 months (1st to 3rd quartile: 5–13 months), there were 45 major cardiac events (4 deaths, 11 nonfatal myocardial infarctions, and 30 late [≥6 months] coronary revascularizations). At Cox analysis, independent prognostic indicators were calcium score > 100 (HR 2.84, 95% CI 1.33–6.07, p = 0.007), significant CAD at CTCA (HR 2.68, 95% CI 1.23–5.82, p = 0.013), and inducible ischemia or CFR <1.9R on LAD on dual imaging stress echo (HR 2.25, 95% CI 1.05–4.84, p = 0.038).
Conclusions Functional and anatomical evaluation using, respectively, dual imaging stress echocardiography and CTCA are both effective modalities to risk stratify patients with chest pain of unknown origin, yielding independent and comparable prognostic value. Compared to CTCA, however, stress echocardiography has the advantage of lower cost and of being free of radiations.
Introduction
Dual imaging of wall motion and coronary flow reserve (CFR) in the left anterior descending coronary artery (LAD) is the current state-of-the-art technique for vasodilator stress echocardiography providing superior diagnostic and prognostic value compared to standard stress testing. In particular, a reduced CFR in the LAD added prognostic information over wall motion analysis in patients with known or suspected coronary artery disease (CAD). Interestingly, the prognostic capability of CFR was not affected by ongoing anti-ischemic therapy.
Computed tomography coronary angiography (CTCA) has emerged as a noninvasive effective diagnostic imaging modality, providing good correlation with invasive measurement of stenosis severity. In particular, CTCA demonstrated high accuracy and negative predictive value in patients referred for chest pain of unknown origin. Unfortunately, CTCA provides a non-negligible radiation exposure with associated cancer risk. In addition, it is unable to assess the hemodynamic meaning of vessel stenosis, as fewer than half of CTCA identified obstructive lesions confirmed by coronary angiography cause ischemia.
This prospective, observational study was aimed at assessing the prognostic value of dual imaging dipyridamole stress echocardiography and CTCA in a cohort of chest pain patients having suspected CAD.
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