Does Proximal Location of Culprit Lesion Confer Worse Prognosis in Patients Undergoing Primary Percutaneous Coronary Intervention for ST Elevation Myocardial Infarction?

STEMI, Revascularization, and Peak Troponin by Adverse Pregnancy Outcomes in Women With Myocardial Infarction

Background

Women with a history of adverse pregnancy outcomes have a higher risk of coronary heart disease. Emerging evidence suggests that women with a history of preeclampsia have a different pattern of overall coronary atherosclerosis and that they at the time of myocardial infarction (MI) more frequently present with ST-segment elevation MI (STEMI) compared to women with no such history.

Objectives

The purpose of this study was to determine whether among women with MI, those with a history of adverse pregnancy outcomes are more likely to present with STEMI or other clinical characteristics indicating a more severe myocardial injury.

Methods

The study sample consisted of 8,320 women aged ≤65 years with first MI in Sweden 2007 to 2022. Regression models were used to estimate the association between adverse pregnancy outcomes (hypertensive disorders of pregnancy [non-preeclamptic hypertension and preeclampsia], small for gestational age [SGA] infant, and preterm delivery) and STEMI, invasive revascularization, and high troponin, while considering known predictors of coronary heart disease.

Results

In total, 3,128 (38%) of women suffered STEMI. The adjusted OR of presenting with STEMI were higher in women with a history of preterm preeclampsia (OR: 1.40; 95% CI: 1.05-1.88), or an SGA infant (OR: 1.30; 95% CI: 1.13-1.50) compared to women with no such history, as well as for in-hospital revascularization. Stratified by infarct type, troponin levels did not differ by adverse pregnancy outcome history.

Conclusions

Among women with a first MI, a history of preterm preeclampsia or SGA infant were associated with STEMI and invasive revascularization.

Cardiogenic shock complicating acute myocardial infarction and multivessel disease: revascularization strategy according to ischemic territory

INTRODUCTION AND OBJECTIVES

The association of revascularization strategy with clinical outcomes according to the ischemic territory of nonculprit lesion has not been documented in patients with acute myocardial infarction complicated by cardiogenic shock (AMI-CS). This study aimed to compare outcomes between culprit-only and immediate multivessel percutaneous coronary intervention (PCI) according to ischemic territory in patients with AMI-CS.

METHODS

A total of 536 patients with AMI-CS and multivessel disease from the SMART-RESCUE registry were categorized according to ischemic territory (nonculprit left main/proximal left anterior descending artery [LM/pLAD] vs culprit LM/pLAD vs no LM/pLAD). The primary outcome was a patient-oriented composite endpoint (POCE) consisting of all-cause death, myocardial infarction, rehospitalization due to heart failure, or repeat revascularization at 1 year.

RESULTS

Among the total population, 108 patients had nonculprit LM/pLAD, 228 patients had culprit LM/pLAD, and 200 patients had no LM/pLAD, with the risk of POCE being higher in patients with large ischemic territory lesions (53.6% vs 53.4% vs 39.6%; P = .02). Multivessel PCI was associated with a significantly lower risk of POCE compared with culprit-only PCI in patients with nonculprit LM/pLAD (40.7% vs 66.9%; HR, 0.52; 95%CI, 0.29-0.91; P=.02), but not in those with culprit LM/pLAD (P=.46) or no LM/pLAD (P=.47). A significant interaction existed between revascularization strategy and large nonculprit ischemic territory (P=.03).

CONCLUSIONS

Large ischemic territory involvement was associated with worse clinical outcomes in patients with AMI-CS and multivessel disease. Immediate multivessel PCI might improve clinical outcomes in patients with a large nonculprit ischemic burden.

Deep Learning-Based Automated Labeling of Coronary Segments for Structured Reporting of Coronary Computed Tomography Angiography in Accordance With Society of Cardiovascular Computed Tomography Guidelines

PURPOSE

To evaluate a novel deep learning (DL)-based automated coronary labeling approach for structured reporting of coronary artery disease according to the guidelines of the Society of Cardiovascular Computed Tomography (CT) on coronary CT angiography (CCTA).

PATIENTS AND METHODS

A retrospective cohort of 104 patients (60.3 ± 10.7 y, 61% males) who had undergone prospectively electrocardiogram-synchronized CCTA were included. Coronary centerlines were automatically extracted, labeled, and validated by 2 expert readers according to Society of Cardiovascular CT guidelines. The DL algorithm was trained on 706 radiologist-annotated cases for the task of automatically labeling coronary artery centerlines. The architecture leverages tree-structured long short-term memory recurrent neural networks to capture the full topological information of the coronary trees by using a two-step approach: a bottom-up encoding step, followed by a top-down decoding step. The first module encodes each sub-tree into fixed-sized vector representations. The decoding module then selectively attends to the aggregated global context to perform the local assignation of labels. To assess the performance of the software, percentage overlap was calculated between the labels of the algorithm and the expert readers.

RESULTS

A total number of 1491 segments were identified. The artificial intelligence-based software approach yielded an average overlap of 94.4% compared with the expert readers' labels ranging from 87.1% for the posterior descending artery of the right coronary artery to 100% for the proximal segment of the right coronary artery. The average computational time was 0.5 seconds per case. The interreader overlap was 96.6%.

CONCLUSIONS

The presented fully automated DL-based coronary artery labeling algorithm provides fast and precise labeling of the coronary artery segments bearing the potential to improve automated structured reporting for CCTA.

The Incidence and Impact of Permanent Right Ventricular Infarction on Left Ventricular Infarct Size in Patients With Inferior ST-Segment Elevation Myocardial Infarction

Mounting evidence shows that right ventricle (RV) function carries independent prognostic influence in various disease states. This study aimed to investigate the incidence and impact of permanent RV infarction in patients with inferior ST-segment elevation myocardial infarction (STEMI) and culprit lesion in the right coronary artery (RCA). In this substudy of the DANAMI-3 (DANish Study of Optimal Acute Treatment of Patients with ST-segment Elevation Myocardial Infarction) trial, cardiac magnetic resonance was performed in 291 patients at day 1 and follow-up 3 months after primary percutaneous coronary intervention of 674 patients with STEMI with the culprit lesion in the RCA. Final infarct was assessed using late gadolinium enhancement on cardiac magnetic resonance at 3 months. Patients with permanent RV infarction (20%) had lower ventricular function at follow-up; RV ejection fraction (EF) 47% ±6 versus 50% ± 5 (p <0.005) and left ventricular (LV) EF 56% ± 8 versus 60% ± 9 (p <0.006). Furthermore, patients with permanent RV infarction had a higher incidence of microvascular obstruction 39 (67%) versus 81 (39%) (p <0.001), larger final LV infarct size 16% ±8 versus 10% ± 8 (p <0.001) and larger LV area at risk 33% ± 10 versus 29% ± 9 (p <0.001). Permanent RV infarction was an independent predictor of final LV infarct size (p <0.001) but was not associated with LVEF (β = -0.0; p = 0.13) in multivariable analyses. In conclusion, permanent RV infarction was seen in 20% of patients with inferior STEMI and culprit lesion in RCA and independently predicted final LV infarct size. However, permanent RV infarction did not predict overall LV function. LGE was used to detect infarct location and quantify infarct size.¹⁷ LGE in RV free wall on follow-up CMR was considered as permanent infarction. LGE images were obtained 10 minutes after intravenous injection of 0.1-mmol/kg body weight of gadolinium-based contrast (Gadovist; Bayer Schering, Berlin, Germany) using an electrocardiogram (ECG)-triggered inversion-recovery sequence. The inversion time was adjusted to null the signal from the normal myocardium. Short-axis images were acquired from the atrioventricular plane to the apex with adjacent 8-mm slices. The remaining protocol has been described previously.¹⁶.

Assessment of Selected Baseline and Post-PCI Electrocardiographic Parameters as Predictors of Left Ventricular Systolic Dysfunction after a First ST-Segment Elevation Myocardial Infarction

OBJECTIVE

To assess the performance of ten electrocardiographic (ECG) parameters regarding the prediction of left ventricular systolic dysfunction (LVSD) after a first ST-segment-elevation myocardial infarction (STEMI).

METHODS

We analyzed 249 patients (74.7% males) treated with primary percutaneous coronary intervention (PCI) included into a single-center cohort study. We sought associations between baseline and post-PCI ECG parameters and the presence of LVSD (defined as left ventricular ejection fraction [LVEF] ≤ 40% on echocardiography) 6 months after STEMI.

RESULTS

Patients presenting with LVSD (n = 52) had significantly higher values of heart rate, number of leads with ST-segment elevation and pathological Q-waves, as well as total and maximal ST-segment elevation at baseline and directly after PCI compared with patients without LVSD. They also showed a significantly higher prevalence of anterior STEMI and considerably wider QRS complex after PCI, while QRS duration measurement at baseline showed no significant difference. Additionally, patients presenting with LVSD after 6 months showed markedly more severe ischemia on admission, as assessed with the Sclarovsky-Birnbaum ischemia score, smaller reciprocal ST-segment depression at baseline and less profound ST-segment resolution post PCI. In multivariate regression analysis adjusted for demographic, clinical, biochemical and angiographic variables, anterior location of STEMI (OR 17.78; 95% CI 6.45-48.96; p < 0.001), post-PCI QRS duration (OR 1.56; 95% CI 1.22-2.00; p < 0.001) expressed per increments of 10 ms and impaired post-PCI flow in the infarct-related artery (IRA; TIMI 3 vs. <3; OR 0.14; 95% CI 0.04-0.46; p = 0.001) were identified as independent predictors of LVSD (Nagelkerke's pseudo R2 for the logistic regression model = 0.462). Similarly, in multiple regression analysis, anterior location of STEMI, wider post-PCI QRS, higher baseline number of pathological Q-waves and a higher baseline Sclarovsky-Birnbaum ischemia score, together with impaired post-PCI flow in the IRA, higher values of body mass index and glucose concentration on admission were independently associated with lower values of LVEF at 6 months (corrected R2 = 0.448; p < 0.00001).

CONCLUSIONS

According to our study, baseline and post-PCI ECG parameters are of modest value for the prediction of LVSD occurrence 6 months after a first STEMI.

Culprit lesion location and outcomes in patients with multivessel disease and infarct-related cardiogenic shock: a core laboratory analysis of the CULPRIT-SHOCK trial

BACKGROUND

Critical culprit lesion locations (CCLL) such as left main (LM) and proximal left anterior descending (LAD) are associated with worse clinical outcome in myocardial infarction without cardiogenic shock (CS).

AIMS

We aimed to assess whether CCLL identify a subgroup of patients with poorer prognosis when presenting with CS.

METHODS

In the CULPRIT-SHOCK trial, a core laboratory reviewed all coronary angiograms to identify CCLL. A CCLL was defined as a culprit lesion with a >70% diameter stenosis of the LM, LM equivalent (>70% diameter stenosis of both proximal LAD and proximal circumflex), proximal LAD or last remaining vessel. We evaluated the primary study endpoint of the CULPRIT-SHOCK trial according to CCLL.

RESULTS

A total of 269 (43%) out of 626 patients eligible for this analysis had a CCLL. Death or renal replacement therapy within 30 days, death within 30 days and death within one year were significantly higher in the CCLL than in the non-CCLL group (58.4% vs 43.4%, p<0.001, 55.8% vs 39.5%, p<0.001, 61.0% vs 44.5%, p<0.001, respectively). This was consistent after adjustment for baseline and angiographic characteristics. No interaction with the randomisation group (culprit lesion-only or immediate multivessel PCI) was found.

CONCLUSIONS

CCLL is frequent in CS and independently associated with worse clinical outcomes irrespective of the revascularisation strategy.

TRIAL REGISTRATION

www.clinicaltrials.gov NCT01927549.

Comparing the clinical and prognostic impact of proximal versus nonproximal lesions in dominant right coronary artery ST-elevation myocardial infarction

OBJECTIVE

To evaluate the prognostic significance of culprit lesion location in dominant right coronary artery (RCA) ST-elevation myocardial infarction (STEMI).

BACKGROUND

In RCA STEMI, proximal culprit lesions have been shown to have higher rates of acute complications such as bradycardia and cardiogenic shock (CS) but data on mortality is limited.

METHODS

We retrospectively identified and analyzed data from consecutive patients with a dominant RCA STEMI who underwent either primary or rescue percutaneous coronary intervention (PCI) between January 2003 and December 2016. We compared the rates of sustained ventricular tachycardia (VT), CS, intra-aortic balloon pump (IABP), temporary cardiac pacing (TCP) and death between culprit lesions located proximal and distal to the origin of the last right ventricular (RV) marginal artery >1 mm in diameter.

RESULTS

The 939 patients were included; 599 (63.7%) had a proximal lesion and 340 (36.3%) had a nonproximal lesion. The 801 (85.3%) underwent primary PCI and 138 (14.7%) underwent rescue PCI. There was no difference in first medical contact to balloon or fibrinolysis times between the groups; p = .98 and .71. There was no significant difference in the rate of sustained VT (3.0%vs. 3.2%, p = .85) but proximal lesions were more likely to develop CS (10.9%vs. 5.8%, p = .01), require IABP (7.3%vs.2.9%, p < .01) and TCP (6.3%vs. 2.6%, p = .01). Thirty-day mortality was higher for proximal lesions (5.0%vs. 0.9%, p < .01) particularly for those with CS (35.3%vs. 10.0%, p = .05).

CONCLUSION

Culprit lesions located proximal to the origin of the last RV marginal artery had a higher rate of acute complications such as CS and mortality.

Clinical and angiographic characteristics of patients with spontaneous reperfusion in ST-segment elevation myocardial infarction

This study aims to investigate the clinical and angiographic characteristics of patients with spontaneous reperfusion in ST-segment elevation myocardial infarction (STEMI).A total of 519 patients with STEMI were enrolled in this study, who underwent primary percutaneous coronary intervention (PCI) treatments at Beijing Anzhen Hospital from January 2015 to December 2018. The patients were divided into 2 groups according to the TIMI flow grade before primary PCI, the non-spontaneous reperfusion group (TIMI flow grade 0-II) and the spontaneous reperfusion group (TIMI flow grade III). The incidence rate, the clinically relevant factors, and the features of the coronary angiographic lesions of spontaneous reperfusion from the 2 groups were recorded and analyzed.There were significant differences between the 2 groups in age, CTnI peak value, high thrombus burden, and locations of lesions in the distant of left anterior descending artery (LAD) (P = .000, .000, .002, .000, and .003, respectively). However, there were no significant differences between the groups in other clinic aspects including gender, hypertension, diabetes mellitus, smoking history, hyperlipemia, angina pectoris history, culprit vessel distribution, lesion distribution in left circumflex artery (LCX) and right coronary artery (RCA), and collateral circulation (P > .05 for all).Compared to the patients without spontaneous reperfusion, patients with spontaneous reperfusion were younger in age, lower in CTnI peak value, and higher in thrombosis burden, with culprit lesions mostly located in the distant of LAD.

Post percutaneous coronary interventional outcomes on proximal vs non-proximal lesions of the left and right coronary arteries: A systematic review and meta-analysis

BACKGROUND

The prognosis of patients with coronary artery disease is mainly related to the extent of myocardium at risk. Proximal coronary arteries, especially the proximal left anterior descending coronary artery (LAD), supply a large part of the myocardium. In this analysis, we aimed to systematically compare the post percutaneous coronary interventional (PCI) outcomes observed with proximal vs non-proximal lesions of the left and right coronary arteries.

METHODS

MEDLARS Online, Excerpta Medica database, www.ClinicalTrials.gov, and the Cochrane databases were searched for relevant studies comparing the post PCI outcomes reported on proximal vs non-proximal lesions of the coronary arteries. RevMan software version 5.3 was used to analyze the data to generate respective results. Odds ratios (OR) and 95% confidence intervals (CI) were derived to represent the results appropriately.

RESULTS

Six studies with a total number of 11,109 participants who were enrolled between 1990 and 2015 were included in this analysis. The current results showed major adverse cardiac events (MACEs) (OR: 1.28, 95% CI: 1.14-1.45; P = .0001) and mortality (OR: 1.70, 95% CI: 1.43-2.03; P = .00001) to be significantly higher with proximal compared to non-proximal coronary lesions irrespective of the follow-up time periods. However, re-infarction (OR: 1.05, 95% CI: 0.80-1.38; P = .71), repeated revascularization (OR: 1.08, 95% CI: 0.92-1.27; P = .35) and stent thrombosis (OR: 0.59, 95% CI: 0.27-1.31; P = .20) were not significantly different.When patients specifically with LAD lesions were compared with associated non-proximal lesions, mortality was still significantly higher with proximal lesions (OR: 2.26, 95% CI: 1.52-3.36; P = .0001). However, when patients with right proximal coronary artery lesions were compared with the corresponding non-proximal lesions, no significant difference was observed in mortality.

CONCLUSION

In-hospital and long-term MACEs and mortality were significantly higher in patients with proximal compared to non-proximal coronary lesions following PCI. In addition, mortality was significantly higher in patients with proximal LAD lesions whereas no significant difference was observed in patients with right proximal coronary artery lesions. Larger trials should further confirm these hypotheses.

Comparison of short-term clinical outcomes of proximal versus nonproximal lesion location in patients treated with primary percutaneous coronary intervention for ST-elevation myocardial infarction: The PROXIMITI study

OBJECTIVES

The objective of this study was to investigate the association of proximal and nonproximal location of culprit coronary lesions with clinical outcomes of patients presenting with ST-elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention (PCI).

BACKGROUND

Proximal culprit lesion location in patients presenting with STEMI is associated with increased mortality when compared to distal culprit lesions in the thrombolytic era. The impact of lesion location on clinical outcomes in the era of PCI remains unclear.

METHODS

We analyzed 3,283 patients with STEMI who enrolled in the Victorian Cardiac Outcomes Registry. We compared outcomes in those with proximal lesion location versus patients with nonproximal location.

RESULTS

Of 3,283 participants, 1,376 (41.9%) had a proximal lesion location. Patients with proximal lesion location presented with greater rates of cardiogenic shock and out-of-hospital cardiac arrest, and left ventricular systolic dysfunction, all P < .01. Procedural success rates were similar (96% vs. 95%, P = .08). Patients with proximal lesion location had higher rates of in-hospital and 30-day mortality, major adverse cardiac events (MACE; mortality, myocardial infarction, stent thrombosis, and unplanned revascularization) and major adverse cardiac and cerebrovascular events (MACCE; MACE, and stroke) compared to the nonproximal group, all P < .001. However, on multivariable regression analysis, proximal lesion location was not independently associated with MACE during in-hospital stay or at 30-days (OR 1.32, 95% CI 0.95-1.83, P = .09 and OR 1.23, 95% CI 0.92-1.65, P = .15) respectively.

CONCLUSIONS

Patients with proximal lesion location had greater hemodynamic instability and higher-risk features; however, proximal lesions per se were not independently associated with worse clinical outcomes compared to nonproximal lesions.

Automatic identification of coronary tree anatomy in coronary computed tomography angiography

An automatic coronary artery tree labeling algorithm is described to identify the anatomical segments of the extracted centerlines from coronary computed tomography angiography (CCTA) images. This method will facilitate the automatic lesion reporting and risk stratification of cardiovascular disease. Three-dimensional (3D) models for both right dominant (RD) and left dominant (LD) coronary circulations were built. All labels in the model were matched with their possible candidates in the extracted tree to find the optimal labeling result. In total, 83 CCTA datasets with 1149 segments were included in the testing of the algorithm. The results of the automatic labeling were compared with those by two experts. In all cases, the proximal parts of main branches including LM were labeled correctly. The automatic labeling algorithm was able to identify and assign labels to 89.2% RD and 83.6% LD coronary tree segments in comparison with the agreements of the two experts (97.6% RD, 87.6% LD). The average precision of start and end points of segments was 92.0% for RD and 90.7% for LD in comparison with the manual identification by two experts while average differences in experts is 1.0% in RD and 2.2% in LD cases. All cases got similar clinical risk scores as the two experts. The presented fully automatic labeling algorithm can identify and assign labels to the extracted coronary centerlines for both RD and LD circulations.

Clinical and Angiographic Predictors of Microvascular Dysfunction in ST-Segment Elevation Myocardial Infarction

PURPOSE

We aimed to discover clinical and angiographic predictors of microvascular dysfunction using the index of microcirculatory resistance (IMR) in patients with ST-segment elevation myocardial infarction (STEMI).

MATERIALS AND METHODS

We enrolled 113 patients with STEMI (age, 56±11 years; 95 men) who underwent primary percutaneous coronary intervention (PCI). The IMR was measured with a pressure sensor/thermistor-tipped guidewire after primary PCI. The patients were divided into three groups based on IMR values: Low IMR [<18 U (12.9±2.6 U), n=38], Mid IMR [18-31 U (23.9±4.0 U), n=38], and High IMR [>31 U (48.1±17.1 U), n=37].

RESULTS

The age of the Low IMR group was significantly lower than that of the Mid and High IMR groups. The door-to-balloon time was <90 minutes in all patients, and it was not significantly different between groups. Meanwhile, the symptom-onset-to-balloon time was significantly longer in the High IMR group, compared to the Mid and Low IMR groups (p<0.001). In the high IMR group, the culprit lesion was found in a proximal location significantly more often than in a non-proximal location (p=0.008). In multivariate regression analysis, age and symptom-onset-to-balloon time were independent determinants of a high IMR (p=0.013 and p=0.003, respectively).

CONCLUSION

Our data suggest that age and symptom-onset-to-balloon time might be the major predictors of microvascular dysfunction in STEMI patients with a door-to-balloon time of <90 minutes.

Myocardial Blood Flow and Flow Reserve in Proximal and Mid-to-Distal Lesions of Left Anterior Descending Artery Measured By N-13 Ammonia PET/CT

PURPOSE

The purpose of this study is to compare the myocardial blood flow (MBF) and flow reserve (MFR) between proximal and mid-to-distal lesions of the left anterior descending artery (pLAD and mdLAD, respectively) using N-13 ammonia positron emission tomography/computed tomography (PET/CT).

METHODS

Subjects were 11 patients (six men and five women, mean age 64.5 years) with known coronary artery disease (CAD) involving LAD studied by N-13 ammonia PET/CT. They were divided into two groups by the location of stenotic lesions, i.e. pLAD versus mdLAD. Global and regional MBF and MFR were measured and compared. Characteristics of perfusion defects including the number of involved segments, basal area involvement, location, size, and shape were also compared between the two groups.

RESULTS

The regional MFR in mid-anterior segment was significantly lower in pLAD group (1.80 ± 0.35 vs 2.76 ± 1.13 for pLAD and mdLAD groups, respectively, p = 0.034), while global MFR was not different (2.10 ± 1.10 vs 2.34 ± 0.84). Both stress and rest MBF in LAD territories were not different in both groups. The size of the perfusion defects were significantly larger in pLAD group (44.0 ± 11.5 % vs 21.1 ± 15.8 %, p = 0.041). Other characteristics such as location, basal area involvement, and shape were not significantly different between two groups.

CONCLUSIONS

The proximal lesion makes lower MFR in the mid-anterior segment and larger perfusion defect in the LAD territory but comparable MBF compared with mdLAD lesion.

Comparison of long-term clinical and 1-year angiographic outcomes after primary stenting (-12 hours) and late reperfusion (12 hours-) using sirolimus-eluting stents for ST-segment elevated myocardial infarctions: a propensity score matching analysis

OBJECTIVE

We compared the long-term clinical and 1-year angiographic outcomes in ST-segment elevation myocardial infarction (STEMI) patients who presented between 12 to 48 hours after symptom onset and underwent emergent procedures (late reperfusion) using sirolimus-eluting stents (SES; Cypher Bx Velocity) with those of primary stenting patients who presented within 12 hours.

METHODS

The study design was a retrospective, nonrandomized single-center study in which the investigations were conducted in October 2012 following the enrollment of consecutive STEMI patients treated with late reperfusion (n=75) and primary stenting using SES (n=386) between September 2004 and May 2007. The incidence of the primary end points (cardiac death, nonfatal recurrent MI and definite stent thrombosis) after late reperfusion (6.7%; mean follow-up, 2,176±742 days) was not significantly different from that observed after primary stenting (8.5%; 2,237±722 days) (p=0.59). The incidence of the secondary end point (binary in-stent restenosis: % diameter stenosis greater than 50% on secondary angiography at approximately one year) after late reperfusion (11.1%, n=54) was not statistically different from that observed after primary stenting (8.0%, n=276) (p=0.45). Using a propensity score matching analysis, the incidences of the primary (6.7%, n=75) and secondary (11.3%, n=53) end points after late reperfusion were not found to be significantly different from those observed after primary stenting (8.0% and 9.4%) (p=0.75 and 0.75, respectively).

CONCLUSION

The present small study showed the long-term clinical and 1-year angiographic outcomes after late reperfusion using SES for STEMI patients in emergent procedures in daily practice to be statistically equivalent to those observed after primary stenting using SES for STEMI patients.

Prehospital 12-Lead Electrocardiogram within 60 Minutes Differentiates Proximal versus Nonproximal Left Anterior Descending Artery Myocardial Infarction

Introduction

Acute anterior myocardial infarctions caused by proximal left anterior descending (LAD) artery occlusions are associated with a higher morbidity and mortality. Early identification of high-risk patients via the 12-lead electrocardiogram (ECG) could assist physicians and emergency response teams in providing early and aggressive care for patients with anterior ST-elevation myocardial infarctions (STEMI). Approximately 25% of US hospitals have primary percutaneous coronary intervention (PCI) capability for the treatment of acute myocardial infarctions. Given the paucity of hospitals capable of PCI, early identification of more severe myocardial infarction may prompt emergency medical service routing of these patients to PCI-capable hospitals. We sought to determine if the 12 lead ECG is capable of predicting proximal LAD artery occlusions.

Methods

In a retrospective, post-hoc analysis of the Pre-Hospital Administration of Thrombolytic Therapy with Urgent Culprit Artery Revascularization pilot trial, we compared the ECG findings of proximal and nonproximal LAD occlusions for patients who had undergone an ECG within 180 minutes of symptom onset.

Results

In this study, 72 patients had anterior STEMIs, with ECGs performed within 180 minutes of symptom onset. In patients who had undergone ECGs within 60 minutes (n = 35), the mean sum of ST elevation (STE) in leads V1 through V6 plus ST depression (STD) in leads II, III, and aVF was 19.2 mm for proximal LAD occlusions and 11.7 mm for nonproximal LAD occlusions (P = 0.007). A sum STE in V1 through V6 plus STD in II, III, and aVF of at least 17.5 mm had a sensitivity of 52.3%, specificity of 92.9%, positive predictive value of 91.7%, and negative predictive value of 56.5% for proximal LAD occlusions. When the ECG was performed more than 60 minutes after symptom onset (n = 37), there was no significant difference in ST-segment deviation between the 2 groups.

Conclusion

The sum STE (V1-V6) and STD (II, III, aVF) on a 12-lead ECG can be used to predict proximal LAD occlusions if performed within the first hour of symptom onset. This should be considered a high-risk finding and may prompt prehospital direction of such patients to PCI-capable hospitals.

Relative spatial distributions of coronary artery bypass graft insertion and acute thrombosis: a model for protection from acute myocardial infarction

BACKGROUND

Randomized trials have demonstrated coronary artery bypass surgery (CABG) to be superior to percutaneous coronary intervention with respect to long-term mortality and morbidity from myocardial infarction within specific high-risk cohorts. The purpose of this study was to analyze the spatial distribution of coronary artery bypass graft anastomoses relative to acute thromboses in native coronary arteries. We hypothesized that insertion sites of bypass grafts are located distal to sites of acute thrombosis and consequently decrease cardiac morbidity and mortality associated with plaque rupture.

METHODS

We analyzed 168 patients with prior CABG and 208 patients with ST-segment elevation myocardial infarctions (STEMI) presenting to the Brigham and Women's Hospital who underwent coronary angiography. We constructed a spatial map of the coronary arterial bypass graft insertion sites and compared these locations to sites of acute thrombosis leading to STEMI.

RESULTS

Graft insertion sites were consistently located distal to acute thrombosis sites (left anterior descending artery median graft insertion versus median thrombosis site = 72 versus 34 mm, right coronary artery 91 versus 42 mm, left circumflex artery 44 versus 37 mm). Greater than 97% of thrombosis sites were located proximal to 75% of graft insertion sites.

CONCLUSIONS

Coronary arterial bypass grafts provide the coverage of anatomic zones at risk for STEMI. The superior performance of CABG in high risk patients may be attributed to targeting of proximal coronary locations where thrombosis risk is clustered.

Myocardial salvage for ST-elevation myocardial infarction with terminal QRS distortion and restoration of brisk epicardial coronary flow

Recently, it has been reported that large infarcts associated with terminal QRS distortion (QRSDIS) on the admission electrocardiograms of patients with ST-elevation myocardial infarctions (STEMIs) may be caused by a failure to achieve thrombolysis in myocardial infarction (TIMI) grade 3 flow after primary percutaneous coronary intervention (PCI). However, the relationship between QRSDIS and final infarct size when TIMI grade 3 flow could be achieved by primary PCI is still unclear. Sixty-two consecutive patients with first anterior STEMI and who achieved TIMI grade 3 flow by primary PCI were classified into two groups according to the presence (Group A, n = 18) or absence (Group B, n = 44) of QRSDIS. Two weeks after the onset of acute myocardial infarction, Group A had a larger left ventricular (LV) end-systolic volume index (LVESVI) and a lower LV ejection fraction (LVEF) than Group B (LVESVI: 38 +/- 13 vs 31 +/- 12 ml/m(2), P = 0.025: LVEF: 42% +/- 10% vs 51% +/- 10%, P = 0.004). Through multivariate analysis, independent predictors of poor LV systolic function (LVEF < 40%) were determined to be the presence of QRSDIS (odds ratio 21.04, P = 0.021) and proximal left anterior descending artery occlusion (odds ratio 16.15, P = 0.033). Myocardial damage could not be reduced in patients experiencing STEMI with QRSDIS, even when TIMI grade 3 flow could be achieved by primary PCI, as much as in patients experiencing STEMI without QRSDIS.

Distribution and frequency of thin-capped fibroatheromas and ruptured plaques in the entire culprit coronary artery in patients with acute coronary syndrome as determined by optical coherence tomography

The aim of this study was to investigate the distribution and frequency of thin-capped fibroatheromas (TCFAs) within the entire length of culprit coronary arteries in patients with acute coronary syndrome. Our population was drawn from 43 consecutive patients with acute coronary syndrome (with or without ST-segment elevation) who underwent optical coherence tomography to visualize the entire culprit coronary artery using a nonocclusive optical coherence tomographic technique. Patients were categorized divided into a TCFA group or a no-TCFA group on the basis of the optical coherence tomographic findings. There were no differences in baseline characteristics or angiographic findings between the 2 groups. High-sensitive C-reactive protein in the TCFA group was significantly higher than in the no-TCFA group (median 3.3 mg/L, interquartile 3.1, vs 1.7 mg/L, interquartile 2.2, p = 0.03). Plaque rupture was found in 28 patients (65%) and multiple plaque ruptures in 5 patients (12%). Optical coherence tomogram revealed 21 TCFAs in 18 patients (42%). Multiple TCFAs were found in the same vessel in 3 patients (7%). The distribution of TCFAs in the right coronary arteries of our subject population was relatively even (proximal 2 [12%], mid 5 [29%], distal 3 [18%], p = 0.42), whereas TCFAs in the left anterior descending artery were common in proximal sites (proximal 6 [27%], mid 2 [9%], distal 0, p = 0.018). In conclusion, the use of optical coherence tomography to look for TCFAs and identify their distribution when combined with C-reactive protein may contribute to forming a strategy for preventing impending coronary events.

Location of acute coronary artery thromboses in patients with and without chronic kidney disease

Patients with chronic kidney disease have high rates of myocardial infarction and death following an initial attack. Proximal location of coronary atherosclerotic lesions has been linked to the risk of acute myocardial infarction and to infarction-associated mortality. To examine if the spatial distribution of lesions differs in patients with and without chronic kidney disease, we used quantitative coronary angiography to measure this in patients with acute coronary thromboses who were having angiography following acute myocardial infarction. Multivariable linear regression was used to adjust for differences in baseline characteristics. Among 82 patients with stage 3 or higher chronic kidney disease, 55.6% of lesions were located within 30 mm and 87.7% were within 50 mm of the coronary ostia. This compared to 34.7 and 71.8%, respectively, among 299 patients without significant kidney disease. Chronic kidney disease was independently and significantly associated with a 7.0 mm decrease in the distance from the coronary ostia to the problem lesion. Our study suggests that a causal link between a more proximal culprit lesion location in patients with chronic kidney disease and their high mortality rates after myocardial infarct is possible and may have important implications for interventions to prevent infarction.

Relation of spontaneous reperfusion in ST-elevation myocardial infarction to more distal coronary culprit narrowings

Spontaneous reperfusion (SR) of the infarct-related artery may occur in patients with ST-segment-elevation myocardial infarctions (STEMIs). Limited data are available on the angiographic characteristics of these patients. The objective of this study was to determine if there are differences in the distance of the culprit lesion from the coronary ostium in patients with STEMIs with and without SR. Patients who presented with acute STEMIs<12 hours after pain onset and who underwent coronary angiography were entered into the study. Measurement of the distance from the coronary ostium to the culprit lesion was performed. A total of 469 patients with STEMIs were included in the study, of whom 77 met criteria for SR (significant relief of chest pain associated with >or=50% resolution of ST-segment elevation on follow-up electrocardiography) and 392 did not. A highly significant difference was seen in ostial to culprit lesion distance, with the culprit lesions in the SR group being more distal than those in the non-SR group (45+/-22 vs 39+/-20 mm, p<0.009). In conclusion, the findings of this study demonstrate that the location of the culprit lesion in patients with STEMIs who undergo SR is more distal in the involved artery than in patients with STEMIs who do not undergo SR.