Long-term prognostic value of QRS score in patients with successfully recanalized coronary chronic total occlusion and construction of a predictive nomogram model

Background: Few studies have evaluated the prognostic value of QRS score in patients with coronary chronic total occlusion (CTO) after successful recanalization.

Methods: A total of 474 patients with successfully recanalized coronary CTO were finally included in our study and were followed up for 34.0±5.3months. They were divided into 3 groups: QRS score≥8, QRS score 4-7 and QRS score 0-3. The primary outcome was composite endpoint of major adverse cardiac and cerebral events (MACCEs). A predictive nomogram was established to predict prognosis for MACCEs, and the predictive accuracy of the nomogram was determined by concordance index.

Results: We found that QRS score correlated moderately with wall motion score index (WMSI) (r=0.551, p<0.001), left ventricular ejection fraction (LVEF) (r=-0.339, p<0.001) and coronary collateral circulation (CCC) (r=-0.569, p<0.001). During follow-up, patients with higher QRS score were observed to undergo poor prognosis. After multivariable adjustment, QRS score was still a significant independent predictor for MACCEs [(hazard ratio 1.28, 95% CI 1.18-1.39, p<0.001) in model 1,(hazard ratio 1.30, 95% CI 1.21-1.41, p<0.001) in mode2] and mortality[(hazard ratio 1.33, 95% CI 1.14-1.57, p<0.001) in model 1, (hazard ratio 1.49 , 95% CI 1.24-1.79, p<0.001) in model 2]. Moreover, the nomogram could more accurately predict 3-year MACCEs (c-index: 0.84).

Conclusion: QRS score is a strong independent predictor of long-term prognosis in patients with coronary CTO successfully recancalized. The proposed nomograms can be used for the prediction of MACCE in this population.