In a study, published in this issue of Echo Research and Practice, Ntoskas et al. retrospectively analyzed the safety of a cardiac physiologist performing, and interpreting, Dobutamine stress echocardiography (DSE) in of 300 patients undergoing DSE for the detection of inducible reversible ischemia, myocardial viability and valvular heart disease. While safety during the tests themselves did not appear to be compromised with this unsupervised approach, the interpretation of these DSEs causes concerns regarding broad patient safety relative to misread results.
Lijun Qian, Feng Xie, Di Xu and Thomas R Porter
Background: Resting myocardial perfusion (MP) and wall motion (WM) imaging during real time myocardial contrast echocardiography (MCE) improves the detection of coronary artery disease (CAD). However, its prognostic role in different clinical settings (emergency department and outpatient setting) remains unclear.
Methods: A systematic search in PubMed and Embase databases, and the Cochrane library, was conducted to evaluate the role of resting MP and WM in predicting major adverse cardiac events (MACE), including death, nonfatal myocardial infarction (NFMI) and urgent revascularization in patients presenting to either outpatient clinics or emergency departments with suspected symptomatic CAD. Summary receiver operating characteristic (SROC) curves, sensitivity and specificity plots were applied to assess diagnostic performance using RevMan 5.3.
Results: Seven studies met criteria, including 3668 patients (six with follow up ranging from two days to 2.6 years). The relative risk (RR) for predicting MACE in patients with both abnormal resting MP and WM was 6.1 (95% CI, 5.1-7.2) and 14.3 (95% CI, 10.3-19.8) for death/NFMI, when compared to normal resting MP and WM patients. Having both abnormal resting MP and WM was also more predictive of MACE (RR 1.7; 95% CI 1.5-1.9) and death/NFMI (RR, 2.2; 95% CI, 1.8-2.7) when compared to abnormal WM with normal resting MP.
Conclusion: In this meta-analysis of both ED and outpatient clinic presentations for suspected CAD, having both a resting regional MP and WM abnormality identifies the highest risk patient for adverse events.
Nicola Gaibazzi, Filippo Pigazzani, Claudio Reverberi and Thomas R Porter
Myocardium subtended by obstructive coronary artery disease (CAD) may show reduced left ventricle (LV) global longitudinal strain (GLS), as well as early systolic lengthening (ESL) before shortening; these can be measured at rest and may predict obstructive CAD. This study investigated whether baseline resting LV longitudinal strain measurements may be able to detect significant CAD in patients undergoing stress echocardiography (SE) and coronary angiography, who have normal resting wall motion. We selected patients with a clinical indication of coronary angiography who were previously referred for SE. Patients with known CAD, rest wall-motion (WM) abnormalities, or rhythm/conduction abnormalities were excluded. Speckle tracking strain analyses were retrospectively performed on digitally archived 2D video-loops, using vendor independent software. Peak GLS and duration of ESL were recorded. Diagnostic accuracy of each parameter to predict obstructive (≥50%) CAD was assessed and multivariate logistic regression models fitted and compared. Eighty-two patients were enrolled and 49 had significant CAD by quantitative angiography. Patients with CAD were more often male (P=0.01) and more frequently presented with typical angina (P<0.01). Among rest and stress variables, GLS showed a Youden index of 0.665, while SE WM assessment showed a Youden index of 0.599. These were the only two parameters that remained predictive in multivariate analyses. In conclusion, rest GLS demonstrated comparable accuracy with stress-echo data for prediction of angiographically obstructive CAD; it also added significant CAD prediction when combined with clinical data, similar to SE WM assessment.