Risk Stratification by Stress Echocardiography Beyond Wall Motion Analysis

Evaluation of the Prognostic Role of the Wall Motion Score Index and the SYNTAX Score II in Patients with Acute Coronary Syndrome Following Percutaneous Coronary Intervention by Evaluation of Major Adverse Cardiovascular Events at 12-Month Follow-Up

Background

This study aimed to evaluate the wall motion score (WMS) index and the SYNTAX score II (SSII) in patients with acute coronary syndrome (ACS) following percutaneous coronary intervention (PCI) by evaluation of major adverse cardiovascular events (MACEs) at the 12-month follow-up at a single center.

Material/Methods

An observational study of 430 patients with ACS undergoing PCI at the Second Affiliated Hospital of Soochow University over a 1-year period was performed. Baseline data including WMS and SSII were recorded and compared with the rates of MACEs in the study group. WMS and SSII were stratified by the tercile from low to high.

Results

Both WMS and SSII were associated with the rates of MACEs (P<0.001 and P=0.003, respectively). The incidence of MACEs was positively correlated with terciles of the WMS and SSII groups (3.7% vs 1.6% vs 7.0% [P<0.001] and 2.6% vs 5.8% vs 11.6% [P<0.001], lowest to highest, respectively). Logistic regression analyses identified combined predictors for 12-month outcome, including WMS and SSII. The use of a model combining both scores yielded a higher predictive value (area under the curve [AUC]=0.78; 95% confidence interval [CI], 0.733–0.835; P<0.001) than the use of either score alone. Using WMSs alone, the AUC was 0.73 (95% CI, 0.660–0.793; P<0.001). Using SSII alone, the AUC was 0.71 (95% CI, 0.649–0.769; P<0.001).

Conclusions

This study showed that the combined methods of the WMS index and the SSII were predictive factors of MACEs in patients with ACS following PCI at the 12-month follow-up.

Dual imaging stress echocardiography versus computed tomography coronary angiography for 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.

Implication of the continuous prognostic spectrum of Doppler echocardiographic derived coronary flow reserve on left anterior descending artery

The additive prognostic value of coronary flow reserve (CFR) over regional wall motion has been established, but there is more than a binary (normal-abnormal) response in CFR, which can be continuously titrated. We assessed the prognostic value of quartiles of CFR, evaluated by transthoracic Doppler of the left anterior descending coronary artery (LAD), in patients with known or suspected coronary artery disease (CAD). One thousand six hundred twenty patients (1,006 men, 64 +/- 11 years of age) underwent dipyridamole (up to 0.84 mg/kg over 6 minutes) stress echocardiography with CFR evaluation of LAD by Doppler and coronary angiography. Patients were followed up for a median of 19 months. Mean CFR in the entire population was 2.25 +/- 0.65. Stress echocardiogram was positive for ischemia in 480 patients (30%). Obstructive (>or=70% vessel stenosis) CAD at angiography was present in 650 patients (40%). During follow-up, there were 298 events (42 deaths, 73 ST-elevation myocardial infarctions, and 183 non-ST-elevation myocardial infarctions). Patients (n = 399) undergoing revascularization were censored. With the Kaplan-Meier method, the first quartile of CFR (<or=1.80) was associated with a worse (p <0.0001) event rate than other quartiles in the entire population and in patients with no ischemia at stress echocardiography. Furthermore, the second quartile of CFR (1.81 to 2.16) was predictive of increased (p <0.0001) risk compared to the higher quartiles. In conclusion, Doppler echocardiographically derived CFR in LAD is a strong and independent prognostic predictor in patients with known or suspected CAD, but the spectrum of prognostic stratifications is expanded if the response is titrated according to a continuous scale rather than artificially dichotomized.