Clinical Outcomes in Patients with Acute Left Circumflex/Obtuse Marginal Occlusion Presenting with Myocardial Infarction

Clinical Significance of Culprit Vessel Occlusion in Patients With Non-ST-Elevation Myocardial Infarction Who Underwent Percutaneous Coronary Intervention

In patients with non-ST-elevation myocardial infarction (NSTEMI), total occlusion of the culprit coronary artery (OCA) is not uncommon. We sought to determine the frequency and clinical impact of OCA at presentation in a large population of patients presenting with NSTEMI and who underwent systematic early invasive management. We performed a post hoc analysis of the TAO (Treatment of Acute Coronary Syndrome with Otamixaban) randomized trial, which included patients with NSTEMI with systematic coronary angiography within 72 hours. We compared the baseline characteristics and outcomes of patients according to whether the culprit vessel was occluded (thrombolysis in myocardial infarction flow grade [TFG] 0 to 1) or patent (TFG 2 to 3) at presentation. A total of 7,473 patients with NSTEMI with only 1 culprit lesion identified were enrolled, of whom 1,702 patients had OCA (22.8%). In the OCA group, coronary angiography was performed earlier (18 ± 15 vs 20 ± 16 hours, p <0.01), the culprit lesion was less likely to be the left anterior descending artery (26.5% vs 41.4%, p <0.001) but with more frequent angiographic thrombus (49.9% vs 22.7%, p <0.01). Culprit artery percutaneous coronary intervention during the index procedure was also more frequent (88.5% vs 78.1%, p <0.001) but with a lower rate of TFG grade 3 after the procedure and higher subsequent peak troponin I levels (8.3 ± 13.6 µg/L vs 5.6 ± 11.9 µg/L, p <0.001). At day 7, patients with OCA had higher mortality, and this persisted after adjustment on gender, Grace risk score, cardiovascular risk factors, and culprit vessel location (0.9% vs 0.4%, p = 0.02; adjusted odds ratio [OR] = 2.55, 95% confidence interval [CI] 1.23 to 5.29, p = 0.01). The absolute difference of mortality was maintained through 30 days: 1.2% versus 0.8%, p = 0.13; OR: 1.72, 95% CI 0.97 to 3.05, but mortality rates were similar by 180 days: 1.5% versus 1.6%, p = 0.8, adjusted OR = 1.11, 95% CI 0.69 to 1.80, p = 0.66. In conclusion, a significant proportion of patients with NSTEMI have a totally occluded culprit vessel at presentation. These patients are at higher risk of early mortality but not at 6 months.

Early ischemic ST-segment and T-wave changes during balloon angioplasty

BACKGROUND

Acute coronary occlusion results in increased T-wave amplitude and ST-segment elevation in the ECG leads facing the ischemic region.

MATERIAL AND METHODS

We performed continuous ECG recording in 34 patients during balloon occlusion of the left anterior descending (LAD), left circumflex (LCx) and right coronary artery (RCA). Delta (Δ) ST and ΔT amplitudes were calculated by subtracting the preinflation values from the values measured during balloon inflation.

RESULTS

Occlusion of the LAD resulted in greater increase in the amplitude of the T wave than of the ST segment in lead V2 (ΔT +3.4 mm, inter-quartile range [IQR] 1-6 mm; ΔST +1.4 mm, 0.5-3 mm). During RCA occlusion, ΔST and ΔT didn't differ significantly. LCx occlusion resulted in significant differences between ΔST and ΔT in all leads, except aVF and V3-V4. In two patients (LCx), we observed a biphasic ST-T response: an initial negative change of the T-wave amplitude was followed by a positive change in leads V1-V2. In leads II, III, aVF and V4-V6, there was an initial positive change, followed by a final negative change towards the end of the occlusion.

CONCLUSION

Continuous 12‑lead ECG recording during balloon occlusion of the LCx resulted in significant differences between the ΔST and ΔT values in all leads except aVF and V3-V4. LAD and RCA occlusion resulted in less evident differences between the ST-segment and T-wave changes. A change in polarity of T-wave changes during balloon occlusion (initial negative and final positive change, or vice versa) proved to be a rare finding.

The "criminal" artery of de Winter may be the left circumflex artery: A CARE-compliant case report

RATIONALE

De Winter et al first described a new ST-segment elevation myocardial infarction (STEMI)-equivalent pattern associated with acute occlusion of the left anterior descending coronary artery (LAD). Studies show that this pattern has a positive predictive value of 95.2% to 100%. However, some cases of non-STEMI, caused by acute right coronary artery or LAD diagonal branch occlusion, have been reported, which exhibit electrocardiogram (ECG) changes similar to the de Winter pattern. Few cases of de Winter ECG pattern caused by left circumflex artery (LCX) stenosis have been reported.

PATIENT CONCERNS

A 57-year-old man was admitted to the emergency department 12 hours after suffering from oppressive chest pain and diaphoresis. The patient had a history of diabetes and smoking. An initial ECG showed atrial fibrillation, upsloping ST-segment depression at the J point, followed by peaked, positive T waves in leads V2 to V6 and slight ST-segment elevation in lead aVR, with poor R-wave progression. Coronary angiography showed tubular stenosis (up to 95%) of the proximal portion of the LCX.

DIAGNOSIS

LCX stenosis led to a diagnosis of non-STEMI.

INTERVENTIONS

Left coronary artery stenosis was successfully treated with angioplasty and insertion of a drug-eluting stent.

OUTCOMES

The patient's chest pain resolved completely after stent implantation. No myocardial infarction occurred during the 6-month follow-up period.

LESSONS

De Winter ECG pattern cannot be presumed to be associated with LAD stenosis and 18-lead ECG is required to support the identification of the "criminal" artery and to rule out posterior myocardial infarction.

Association of coronary dominance with the severity of coronary artery disease: a cross-sectional study in Shaanxi Province, China

OBJECTIVE

To investigate whether coronary artery dominance is associated with the severity of coronary artery disease (CAD).

DESIGN

Cross-sectional study.

SETTING

Single-centre.

PARTICIPANTS

Between July 2015 and February 2017, 1654 patients who underwent coronary angiography (CAG) were recruited into this cross-sectional study.

MEASUREMENT AND METHODS

According to coronary dominance, patients were classified into left dominance (LD), right dominance (RD) and codominance (CD) based on the CAG results. Multiple linear regression analysis was performed to test the association between severity of CAD and coronary dominance.

RESULTS

The total Gensini score was significantly higher in the RD group than in the left-CD group (42.3±33.6 vs 36.3±29.8; p=0.033). After adjusting for potential confounding factors, the results of multivariate linear regression showed that RD was associated with the severity of CAD (β=6.699, 95% CI 1.193 to 12.205, p=0.017).

CONCLUSIONS

The results suggest that right coronary dominance was associated with the severity of CAD.

Acute myocardial infarction and lesion location in the left circumflex artery: importance of coronary artery dominance

AIMS

Due to the limitations of 12-lead ECG, occlusions of the left circumflex artery (LCX) are more likely to present as non-ST-elevation acute coronary syndrome (NSTEACS) compared with other coronary arteries. We aimed to study mortality in patients with LCX lesions and to assess the importance of coronary artery dominance on triage of these patients.

METHODS AND RESULTS

From the Eastern Danish Heart Registry, 3,632 NSTEACS and 3,907 ST-elevation myocardial infarction (STEMI) consecutive, single-vessel disease patients were included. LCX was the culprit in 25% of NSTEACS and 14% of STEMIs (p<0.001). LCX lesions presented predominantly as STEMI in left dominant coronary arteries compared with NSTEACS (46% vs. 30%, p<0.001). Higher 30-day mortality was found in LCX-STEMI compared with LCX-NSTEACS (HR 7.9, 95% CI: 3.2-19.7, p<0.001) with no difference in long-term mortality (HR 0.9, 95% CI: 0.7-1.2, p=0.5). LCX-NSTEACS were not associated with higher mortality compared with other NSTEACS lesions.

CONCLUSIONS

The 12-lead ECG seems sufficient for triage of patients with LCX lesions as a majority of patients with a large LCX due to a dominant left coronary artery present as STEMI. Patients with LCX-NSTEACS do not have higher mortality compared with patients with LCX-STEMI or NSTEACS with lesions in other coronary territories.

Impact of coronary dominance on in-hospital outcomes after percutaneous coronary intervention in patients with acute coronary syndrome

Objective

This study evaluated the manner in which coronary dominance affects in-hospital outcomes of acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI).

Background

Previous studies have shown that left dominant coronary anatomies are associated with worse prognoses in patients with coronary artery disease.

Methods

Data were analyzed from 4873 ACS patients undergoing PCI between September 2008 and April 2013 at 14 hospitals participating in the Japanese Cardiovascular Database Registry. The patients were grouped based on diagnostic coronary angiograms performed prior to PCI; those with right- or co-dominant anatomy (RD group) and those with left-dominant anatomy (LD group).

Results

The average patient age was 67.6±11.8 years and both patient groups had similar ages, coronary risk factors, comorbidities, and prior histories. The numbers of patients presenting with symptoms of heart failure, cardiogenic shock, or cardiopulmonary arrest were significantly higher in the LD group than in the RD group (heart failure: 650 RD patients [14.7%] vs. 87 LD patients [18.8%], P = 0.025; cardiogenic shock: 322 RD patients [7.3%] vs. 48 LD patients [10.3%], P = 0.021; and cardiopulmonary arrest: 197 RD patients [4.5%] vs. 36 LD patients [7.8%], P = 0.003). In-hospital mortality was significantly higher among LD patients than among RD patients (182 RD patients [4.1%] vs. 36 LD patients [7.8%], P = 0.001). Multivariate logistic regression analysis revealed that LD anatomy was an independent predictor for in-hospital mortality (odds ratio, 1.75; 95% confidence interval, 1.06–2.89; P = 0.030).

Conclusion

Among ACS patients who underwent PCI, LD patients had significantly worse in-hospital outcomes compared with RD patients, and LD anatomy was an independent predictor of in-hospital mortality.

Left circumflex occlusion in acute myocardial infarction (from the National Cardiovascular Data Registry)

Compared to occlusions of other major coronary arteries, patients presenting with acute left circumflex (LCx) occlusion usually have ST-segment elevation on the electrocardiogram <50% of the time, potentially delaying treatment and resulting in worse outcomes. In contemporary practice, little is known about the clinical outcomes of patients with LCx territory occlusion without ST-segment elevation myocardial infarction (STEMI). We identified patients with myocardial infarction from April 2004 to June 2009 in the CathPCI Registry treated with percutaneous coronary intervention for culprit LCx territory occlusion, excluding those with previous coronary artery bypass grafting. Logistic generalized estimating equation modeling was used to compare the outcomes, including in-hospital mortality between patients with STEMI and non-STEMI (NSTEMI) adjusting for differences in the baseline characteristics. Of the 27,711 patients with myocardial infarction and acute LCx territory occlusion, 18,548 (67%) presented with STEMI and 9,163 (33%) with NSTEMI. With the exception of a greater proportion of cardiac risk factors and cardiac history in the NSTEMI group, the demographic and baseline characteristics were clinically similar between the 2 groups, despite the statistical significance resulting from the large population. The patients with STEMI were more likely to have a proximal LCx culprit lesion (63% vs 27%, p <0.0001) and had greater risk-adjusted in-hospital mortality (odds ratio 1.36, 95% confidence interval 1.12 to 1.65, p = 0.002) compared to patients with NSTEMI. In conclusion, acute LCx territory occlusion often presents as NSTEMI, but patients with NSTEMI and occlusion have a lower mortality risk than those with STEMI, possibly because of factors such as the amount of myocardium involved, the lesion location along the vessel, and/or a dual blood supply.