Computerized classification of proximal occlusion in the left anterior descending coronary artery

Proximal occlusion within the left anterior descending (LAD) coronary artery in patients with acute myocardial infarction leads to higher mortality than does nonproximal occlusion. We evaluated an automated program to detect proximal LAD occlusion.All patients with suspected acute coronary syndrome (n = 7,710) presenting consecutively to the emergency department of a local hospital with a coronary angiogram-confirmed flow-limiting lesion and notation of occlusion site were included in the study (n = 711). Electrocardiograms (ECGs) that met ST-segment elevation myocardial infarction (STEMI) criteria were included in the training set (n = 183). Paired angiographic location of proximal LAD and ECGs with ST elevation in the anterolateral region were used for the computer program development (n = 36). The test set was based on ECG criteria for anterolateral STEMI only without angiographic reports (n = 162). Tested against 2 expert cardiologists' agreed reading of proximal LAD occlusion, the algorithm has a sensitivity of 95% and a specificity of 82%.The algorithm is designed to have high sensitivity rather than high specificity for the purpose of not missing any proximal LAD in the STEMI population. Our preliminary evaluation suggests that the algorithm can detect proximal LAD occlusion as an additional interpretation to STEMI detection with similar accuracy as cardiologist readers.     

Transthoracic Doppler echocardiographic coronary flow imaging in identification of left anterior descending coronary artery stenosis in patients with left bundle branch block

Background: Conventional noninvasive methods have well‐known limitations for the detection of coronary artery disease (CAD) in patients with left bundle branch block (LBBB). However, advancements in Doppler echocardiography permit transthoracic imaging of coronary flow velocities (CFV) and measurement of coronary flow reserve (CFR). Our aim was to evaluate the diagnostic value of transthoracic CFR measurements for detection of significant left anterior descending (LAD) stenosis in patients with LBBB and compare it to that of myocardial perfusion scintigraphy (MPS). Methods: Simultaneous transthoracic CFR measurements and MPS were analyzed in 44 consecutive patients with suspected CAD and permanent LBBB. Typical diastolic predominant phasic CFV Doppler spectra of distal LAD were obtained at rest and during a two‐step (0.56–0.84 mg/kg) dipyridamole infusion protocol. CFR was defined as the ratio of peak hyperemic velocities to the baseline values. A reversible perfusion defect at LAD territory was accepted as a positive scintigraphy finding for significant LAD stenosis. A coronary angiography was performed within 5 days of the CFR studies. Results: The hyperemic diastolic peak velocity (44 ± 9 cm/sec vs 62 ± 2 cm/sec; P=0.01) and diastolic CFR (1.38 ± 0.17 vs 1.93 ± 0.3; P=0.001) were significantly lower in patients with LAD stenosis compared to those without LAD stenosis. The diastolic CFR values of <1.6 yielded a sensitivity of 100% and a specificity of 94% in the identification of significant LAD stenosis. In comparison, MPS detected LAD stenosis with a sensitivity of 100% and a specificity of 29%. Conclusions: CFR measurement by transthoracic Doppler echocardiography is an accurate method that may improve noninvasive identification of LAD stenosis in patients with LBBB.     

Septal myocardial perfusion imaging with thallium-201 in the diagnosis of proximal left anterior descending coronary artery disease

The use of myocardial perfusion imaging (MPI) to identify obstructive coronary disease of the left anterior descending coronary artery proximal to the first septal perforator (prox LAD) was studied in 60 patients. Perfusion of the septum and anteroapical areas with thallium-201 injected during exercise was compared to results of coronary arteriography. Septal MPI defect was found in 92.3% of patients with obstruction of the proximal LAD, 27.7% of patients with obstruction of LAD distal to first septal perforator, 0% in patients with obstructions involving right or circumflex arteries, and in 10.5% of patients without coronary disease. Anteroapical MPI defects were found with similar frequency in the three groups with obstructive coronary disease. Septal MPI defect had a sensitivity of 92.3% and specificity of 85.4% in the diagnosis of proximal LAD disease. Normal septal perfusion with thallium-201 virtually excluded proximal LAD disease.     

Giant left anterior descending coronary artery aneurysm

Small atherosclerotic coronary artery aneurysms are a relatively frequent incidental finding at angiography. We report an unusual case in that the aneurysm found was extremely large and therefore potentially at risk of rupture.     

Electrocardiographic manifestations of proximal left anterior descending artery occlusion

We report the case of a 51-year-old woman who presents with a 2-week history of episodes of pressure like chest pain. The initial electrocardiogram was not indicative of myocardial ischemia or infarction and the cardiac enzymes remained normal during the initial hospital day. However, the precordial T waves inverted and progressively deepened on the second hospital day and the patient underwent cardiac catheterization with percutaneous coronary angioplasty and stent placement of the left anterior descending coronary artery with good results. The postprocedure electrocardiogram showed complete resolution of the inverted precordial T waves. The development of new T-wave inversions in the precordial leads of patients presenting with unstable angina is predictive of significant stenosis of the left anterior descending coronary artery. This subgroup of patients has a poor prognosis if medical therapy alone is instituted. Early cardiac catheterization and revascularization is recommended for these patients. Evidence has shown that 75% patients with these electrocardiogram changes who are not revascularized developed extensive anterior wall infarction within a few weeks.     

Isolated anomaly of the left anterior descending coronary artery

An isolated anomaly of the left anterior descending coronary artery arising from the right sinus of Valsalva is described. A review of the literature shows that isolated anomalies of this vessel are very rare. However, the inability to visualize this vessel from the left sinus of Valsalva warrants careful search of the right sinus.     

Simultaneous transesophageal Doppler assessment of coronary flow reserve in the left anterior descending artery and coronary sinus allows differentiation between proximal and non-proximal left anterior descending artery stenoses.

AIM AND METHODS: The role of simultaneous transesophageal Doppler assessment of coronary flow reserve (CFR) in the left anterior descending artery (LAD) and coronary sinus (CS) in the diagnostics of hemodynamically significant LAD stenoses of various localization was studied in 16 CAD patients with angiographically proven >50% stenotic atherosclerosis of the LAD (nine--in the proximal third, seven--in the mid and/or distal third) and 23 healthy volunteers (all men). Dipyridamole was used as a stress agent. The diastolic phase of coronary flow in the LAD and the antegrade phase of coronary flow in the CS were analyzed. CFR in the LAD and CS was calculated in two ways: one--as ratio of peak hyperemic flow velocity to the peak baseline blood flow velocity (CFR by Vp); two--as ratio of volume hyperemic blood flow velocity to the volume baseline blood flow velocity (CFR by VBF). The level of the CFR <2 in both ways of calculation was diagnosed as reduced. RESULTS: It was found that in CAD patients with LAD proximal stenosis the values of CFR in the LAD were significantly lower than those in healthy individuals by both Vp (1.87 +/- 0.43 and 3.54 +/- 0.82; P<0.001) and VBF (1.79 +/- 0.77 and 3.85 +/- 1.25; P<0.01). In proximal stenosis CFR in the LAD by Vp was significantly lower than that in non-proximal stenosis (1.87 +/- 0.43 and 3.31 +/- 1.44; P<0.05). Sensitivity and specificity of CFR <2 in the LAD by Vp in the diagnostics of LAD proximal stenosis were 56% and 97%, respectively; and CFR <2 in the LAD by VBF--89% and 93%, respectively. In CAD patients with both proximal and non-proximal LAD stenoses CFR in the CS by Vp was significantly lower than that in healthy volunteers and was 1.74 +/- 0.53, 1.63 +/- 0.30 and 2.56 +/- 0.87; P<0.05, respectively. Sensitivity and specificity of CFR <2 in the CS by Vp in the diagnostics of hemodynamically significant LAD stenoses were 75% and 70%, respectively. The values of CFR in the CS by VBF in CAD patients and healthy volunteers did not differ significantly. CONCLUSIONS: Thus, simultaneous evaluation of CFR in the LAD and CS makes it possible to diagnose hemodynamically significant LAD stenoses and to differentiate between proximal and non-proximal impairments.     

主动脉球囊反搏在前降支近端病变经皮冠状动脉介入治疗术中的应用

目的将主动脉内球囊反搏(IABP)应用于前降支(LAD)近端病变经皮冠状动脉内支架置入术中,探讨其对患者术中及预后影响。方法收集从2007年1月至2010年12月因LAD近端病变行经皮冠状动脉介入治疗术(PCI)者880例,其中将应用IABP的544例作为IABP组,余未应用IABP的336例为对照组,比较两组术中、术后情况。结果 IABP组术中并发症及住院期间心血管事件总发生率低于对照组,两者比较差异均有统计学意义(χ2=4.12,P<0.05);IABP组术后6个月、12个月左心室舒张末内径(52.23±3.00)mm、(52.80±2.65)mm明显小于对照组(54.06±4.01)mm、(54.86±4.39)mm,术后1个月、6个月、12个月左心室射血分数(51.92±4.16,53.46±4.33,53.88±4.32)明显大于对照组(49.51±4.24,50.65±4.25,51.14±4.39),且IABP组随访心血管事件发生率明显低于对照组,两者比较差异均有统计学意义(χ2=20.76,P<0.05)。结论在IABP辅助下行LAD近端病变PCI术可降低手术操作难度及危险性,并能改善患者预后。     

Mid left anterior descending coronary artery originating from the right coronary artery

Dual connection of the left anterior descending coronary artery to the left and right coronary arteries is a very rare congenital anomaly. In this report we describe two cases in which the mid-position of the left anterior descending coronary artery is connected to the right coronary artery, one directly and the second by way of the infundibular artery. To the best of our knowledge, connection of the mid-position of the left anterior descending to the infundibular artery has not been previously described.     

Progression of left main coronary artery stenosis following left anterior descending coronary artery angioplasty

Although recent clinical experience indicates a high success rate, percutaneous transluminal coronary angioplasty (PTCA) is still associated with serious complications which usually occur during or shortly after the procedure and are principally related to the lesion or segment of vessel being dilated. We report 2 cases of subacute progression within months of left main stenosis following successful, uncomplicated left anterior descending (LAD) coronary PTCA. Identification of left main trunk involvement may mandate earlier follow-up or intervention.     

Prognostic significance of severe narrowing of the proximal portion of the left anterior descending coronary artery

To determine the prognostic importance of significant narrowings involving the proximal left anterior descending coronary artery (LAD), 866 medically treated patients with significant coronary artery disease (CAD) were followed after cardiac catheterization for a mean of 17 months (range 1 to 46). Coronary narrowings in all patients were evaluated based on site relative to large branches and on angiographic severity. Prognosis was best predicted by the presence of at least 70% diameter reductions in the LAD before the first 2 large branches (chi 2 = 16, p = 0.0001). At 3 years, there was a 94% cumulative survival rate in patients with less than 70% stenoses at this location, but an 82% survival rate in patients with 70% or more stenoses (p less than 0.0001). In addition, although the presence of proximal LAD narrowings was the best predictor of prognosis in patients with a low global ejection fraction, this was not so in patients with normal ejection fractions, as this subgroup had an excellent overall prognosis. Thus, the presence and severity of significant stenoses in the proximal LAD are stronger predictors of prognosis than stenoses elsewhere in the major coronary arteries. The presence of an angiographically significant narrowing in this anatomic location is highly correlated with an increased 1- to 3-year mortality rate.     

Minimally invasive coronary artery bypass grafting versus stenting for patients with proximal left anterior descending coronary artery disease

The purpose of this study was to compare the clinical outcomes of stenting and minimally invasive coronary artery bypass grafting (MIDCAB) in patients with proximal left anterior descending (LAD) coronary artery disease. The Patency, Outcome, Economics of Minimally invasive direct coronary bypass (POEM) study demonstrated that MIDCAB had similar safety and long-term efficacy for LAD revascularization compared with conventional coronary artery bypass grafting. Although LAD stenting is superior to conventional balloon angioplasty, whether it is comparable to MIDCAB is not known. We identified a matched population of 429 consecutive patients with 1-vessel disease who underwent elective proximal LAD stenting and compared their clinical outcomes with those of the 152 patients in the MIDCAB group of the POEM study. The in-hospital event rate was similar in both groups, except for a shorter length of hospital stay with LAD stenting compared with MIDCAB (2.68 vs 4.07 days, p <0.0001). At 6-month follow-up, the incidence of death and Q-wave myocardial infarction or that of cerebrovascular accident was not significantly different between these 2 groups. However, target vessel revascularization was significantly higher with LAD stenting than MIDCAB (13.3% vs 6.6%, p = 0.045). In the subgroup of patients without diabetes, all clinical events were similar in both groups, and the benefit of a shorter hospital stay associated with stenting was maintained. Compared with MIDCAB, LAD stenting is associated with higher repeat revascularization rates but offers the advantage of shorter hospitalization. For nondiabetics with proximal LAD disease, stenting may be the revascularization strategy of choice.     

Mammary artery patch reconstruction of left anterior descending coronary artery

Most patients with diffuse coronary disease require endarterectomy for revascularization. In view of the high morbidity and mortality associated with coronary endarterectomy, patch angioplasty and reconstruction of the coronary artery was developed. We retrospectively evaluated 104 patients who underwent mammary artery patch angioplasty of the left anterior descending coronary artery. The procedure consisted of laying open the entire diseased segment of the coronary artery and patching it with an in-situ left internal mammary artery onlay patch, without endarterectomy, in an off-pump procedure. One (0.9%) patient died, 2 (1.8%) suffered perioperative myocardial infarction, and an intraaortic balloon pump was used in 2. The mean blood loss was 224 mL. Intensive care unit stay was 2.5 days, and hospital stay was 7.8 days. At 1-year follow-up, most patients were in New York Heart Association functional class I. Follow-up angiography was carried out in 16 patients and showed good patency of all anastomoses. Arterial patch reconstruction of the left anterior descending coronary artery can be performed safely and effectively in an off-pump procedure, with excellent early and intermediate results.