Diagnosis, performance and added value of assessing ventricular dyssynchrony by phase analysis in patients with three-vessel disease: A single-center cross-sectional study in Mexico

Left ventricular mechanical dyssnchrony: A potential new marker for 3-vessel CAD

“…Indeed, the authors performed early image acquisition 5-10 min after the completion of the stress test, which was crucial to capturing stunning induced impaired myocardial contractility and dyssynchrony. In a study published by our group, a large ischemic burden was not associated with worsening of LVMD indices; 38 while these results seem to contradict what is being proposed and shown by Garcia-Cardenas M et al, 37 the key difference is that post-stress image acquisition was acquired routinely at 30-45 min rather than early 5-10 min. Unlike perfusion parameters that are reflective of changes occurring at time of tracer injection (peak stress), gated parameters (EF and LVMD) reflect changes occurring at time of image acquisition.…”

“…30 Although Garcia-Cardenas M et al did not use change in EF or change in LVMD as variables, the table results showed that average stress EF was higher than resting EF, and average stress SD/BW was lower than rest in the control group, while patients with 3vessel CAD had almost same average values of stress and rest corresponding parameters. 37 While the authors did not show the actual paired changes, it is safe to assume that the 3-vessel CAD cohorts have at least blunted EF and synchrony response. It would have been interesting to see whether changes in BW and EF were better predictors of 3-vessel CAD than absolute stress only parameters as shown in the proposed model.…”

“…35,36 When myocardial stunning occurs during stress testing, there is impaired myocardial contractility and worsening of mechanical synchrony which can be quantified by phase analysis. In the current single-center cross-sectional study from Mexico, Garcia-Cardenas M et al 37 sought to assess the diagnostic performance and added value of LVMD indices by phase analysis of gated SPECT in discriminating patients with 3-vessel CAD from those without CAD. The authors designed paired retrospective sample of gated SPECT images of patients with 3-vessel CAD (n = 237, 84% male, mean age 62 years) and those without CAD (n = 237, 49% male, mean age 64 years).…”

“…The binomial logistic regression model using perfusion and LVMD parameters continued to display similar optimal area under the curve. 37 Diagnosing 3-vessel CAD with SPECT imaging remains however challenging. While the specificity of perfusion parameters and stress LVMD indices is moderate to high (70-92%), the sensitivity of individual parameters is low (43-62%) as shown by Garcia-Cardenas M et al 37 Therefore, an ideal parameter that can be derived from these stress studies with high enough diagnostic accuracy to identify patients with 3-vesel CAD is still lacking.…”

“…37 Diagnosing 3-vessel CAD with SPECT imaging remains however challenging. While the specificity of perfusion parameters and stress LVMD indices is moderate to high (70-92%), the sensitivity of individual parameters is low (43-62%) as shown by Garcia-Cardenas M et al 37 Therefore, an ideal parameter that can be derived from these stress studies with high enough diagnostic accuracy to identify patients with 3-vesel CAD is still lacking. However, a combined model of perfusion and gated parameters, including stress LVMD (stress BW), displayed a high area under the curve and showed good discriminatory ability.…”