Effect of myocardial scar size on the risk of ventricular arrhythmias in patients with chronic total coronary occlusion

BACKGROUND

The presence of an untreated chronic total coronary occlusion (CTO) is associated with a higher risk of ventricular arrhythmias (VAs). This increased risk may be modulated by the presence of an existing scar.

OBJECTIVES

To evaluate whether scar size is associated with VA in patients with an implantable cardioverter-defibrillator (ICD) and a CTO.

METHODS

In this retrospective study we included patients with a CTO that received an ICD between 2005 and 2015. Scar size was estimated using the Selvester QRS score on a baseline 12‑lead ECG. The primary endpoint was any appropriate ICD therapy.

RESULTS

Our study population comprised 148 CTO patients with a median scar size at baseline of 18% (IQR, 9-27%). Patients with a scar size ≥18% more often had a CTO located in the left anterior descending artery and a higher proportion of poor left ventricular function (<35%) and infarct-related CTO compared to patients with a smaller scar size (<18%). During a median follow-up of 35 months (interquartile range [IQR], 8-60 months), 42 patients (28%) received appropriate ICD therapy. The cumulative 5-year event rate was higher in the patients with a large scar in comparison to those with a smaller or no scar (36% versus 19%, P = 0.04). Multivariable Cox regression analysis demonstrated that large scar and diabetes mellitus were independent factors associated with appropriate ICD therapy.

CONCLUSION

In ICD recipients with an untreated CTO, a larger scar is an independent factor associated with an increased risk of VA.

Prognostic Significance of a Combination of QRS Score and E/e' Obtained 2 Weeks After the Onset of ST-Elevation Myocardial Infarction

BACKGROUND

The early mitral inflow velocity to mitral early diastolic velocity ratio (E/e') and electrocardiogram (ECG) determination of QRS score are useful for risk stratification in patients with ST-elevation myocardial infarction (STEMI).Methods and Results:In this study, 420 consecutive patients (357 male; mean [±SD] age 63.6±12.2 years) with first-time STEMI who successfully underwent primary percutaneous coronary intervention within 12 h of symptom onset were followed-up for 5 years (median follow-up 67 months). Echocardiography, ECG, and blood samples were obtained 2 weeks after onset. Infarct size was estimated by the QRS score after 2 weeks (QRS-2wks) and creatine phosphokinase-MB concentrations (peak and area under the curve). The primary endpoint was death from cardiac causes or rehospitalization for heart failure (HF). During follow-up, 21 patients died of cardiac causes and 62 had HF. Multivariate Cox proportional hazard analysis showed that mean E/e' (hazard ratio [HR] 1.152; 95% confidence interval [CI] 1.088-1.215; P<0.0001), QRS-2wks (HR 1.153; 95% CI 1.057-1.254; P<0.0001), and hypertension (HR 1.702; 95% CI 1.040-2.888; P=0.03) were independent predictors of the primary endpoint. Kaplan-Meier curve analysis showed that patients with QRS-2wks >4 and mean E/e' >14 were at an extremely high risk of cardiac death or HF (log rank, χ²=116.3, P<0.0001).

CONCLUSIONS

In patients with STEMI, a combination of QRS-2wks and mean E/e' was a simple but useful predictor of cardiac death and HF.

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.

Athens QRS Score as a Predictor of Coronary Artery Disease in Patients With Chest Pain and Normal Exercise Stress Test

Background

The diagnostic value of the Athens QRS score to detect obstructive coronary artery disease CAD in patients with otherwise normal exercise stress test remains unclear.

Methods and Results

We analyzed 458 patients who underwent exercise stress test with or without myocardial perfusion imaging within 2 months of coronary angiography from 2008 to 2011. Patients (n=173) with abnormal stress test based on ST segment criteria were excluded. The Athens QRS score ≤5 was defined as abnormal. In our study cohort, 285 patients met the inclusion criteria and were divided into 2 groups: low Athens QRS score (LQRS, n=56), with QRS score ≤5 and normal Athens QRS score normal Athens QRS score, n=229), with QRS score >5. The presence of single‐vessel and multivessel obstructive CAD was higher in LQRS than in normal Athens QRS score patients (47% versus 7.5% and 30% versus 3.8%, respectively, all P<0.001). Logistic regression analysis showed that the likelihood of CAD was strongly and independently associated with LQRS (odds ratio=36.81, 95% CI: 10.77–120.47), diabetes (odds ratio=6.49, 95% CI: 2.41–17.49), lower maximum heart rate (odds ratio=0.92, 95% CI: 0.88–0.95, all P<0.001), and older age (odds ratio=1.93, CI: 1.88–1.97, P=0.002).

Conclusions

In a clinical cohort of patients with chest pain and normal exercise stress test, LQRS score is a strong independent predictor of presence of CAD. LQRS patients have a 6‐fold higher prevalence of CAD and may warrant further evaluation even with reassuring exercise stress test.

Relationship between QRS score and microvascular obstruction after acute anterior myocardial infarction

BACKGROUND

The QRS score on electrocardiogram (ECG) in patients with myocardial infarction (MI) reportedly reflects the severity of myocardial damage. The presence of microvascular obstruction (MO) assessed by cardiac magnetic resonance (CMR) imaging is associated with irreversible myocardial damage. MO assessed by CMR is known to be a predictor for adverse clinical outcome after ST-elevation MI. The aim of the present study was to examine the relationship between QRS score and MO in acute anterior MI patients.

METHODS

Sixty-two patients with first acute anterior MI who successfully underwent primary percutaneous coronary intervention (PCI) were enrolled. The QRS score after PCI on admission ECG was calculated by a Selvester-Wagner QRS scoring system. CMR imaging was performed at 11.4±3.9 days after MI. MO was defined as delayed enhancement with contrast-devoid core. Patients were divided into two groups as follows: 37 patients who showed MO (MO group) and 25 patients who did not show it (non-MO group).

RESULTS

The QRS score was significantly greater in the MO group than in the non-MO group. The QRS score significantly correlated with MO volume (r=0.418, p=0.010). Multivariate analysis showed that the QRS score (odds ratio 1.362, 95% CI: 1.038-1.951, p=0.024) and the peak creatine kinase levels (odds ratio 1.001, 95% CI: 1.000-1.002, p<0.001) were independent predictors for MO.

CONCLUSIONS

Our results indicate that the QRS score derived from simple and widely available ECG may be a useful parameter for assuring the presence of MO.