Alejandro Solodky

New Electrocardiographic Criteria for Predicting Either the Right or Left Circumflex Artery as the Culprit Coronary Artery in Inferior Wall Acute Myocardial Infarction

Two readily obtainable measurements on the admission electrocardiogram-a higher ST-segment elevation in lead III than in lead II and a greater ST-segment depression in lead aVL than in lead I-can distinguish right coronary artery from left circumflex artery-related acute inferior wall myocardial infarction.

Prediction of the level of left anterior descending coronary artery obstruction during anterior wall acute myocardial infarction by the admission electrocardiogram

T he ability to predict the exact site of the occlusion of the infarct-related artery by a noninvasive method shortly after admission to the hospital may help the clinician in estimating the myocardial area at risk and planning therapeutic interventions. This is important especially for anterior wall acute myocardial infarction (M), because proximal left anterior descending (LAD) coronary artery disease has a poor prognosis.‘” The electrocardiogram is quite reliable in detecting anterior wall AMF9 or infarction caused by LAD coronary artery obstruction. l”,ll Based on the electrocardiogram, several subtypes of anterior wall AMI are recognized (anteroseptal, anterolateral, apical, and so forth)12; however, correlation of the various electrocardiographic patterns with the exact anatomic location of the infarct as determined by autopsy is poor.7,8,12 This study assesses the value of ST changes in the various electrocardiographic leads during evolving anterior wall AMI in predicting the location of the LAD coronary artery obstruction in relation to the origin of the tirst diagonal branch. All patients admitted to the coronary care unit with AM from July 1988 to November I992 were evaluated retrospectively. Patients who underwent coronary angi-

Treatment of Aspirin-Resistant Patients With Omega-3 Fatty Acids Versus Aspirin Dose Escalation

OBJECTIVESnThe aim of this study was to evaluate whether addition of omega-3 fatty acids or increase in aspirin dose improves response to low-dose aspirin among patients who are aspirin resistant.nnnBACKGROUNDnLow response to aspirin has been associated with adverse cardiovascular events. However, there is no established therapeutic approach to overcome aspirin resistance. Omega-3 fatty acids decrease the availability of platelet arachidonic acid (AA) and indirectly thromboxane A2 formation.nnnMETHODSnPatients (n = 485) with stable coronary artery disease taking low-dose aspirin (75 to 162 mg) for at least 1 week were screened for aspirin response with the VerifyNow Aspirin assay (Accumetrics, San Diego, California). Further testing was performed by platelet aggregation. Aspirin resistance was defined by > or =2 of 3 criteria: VerifyNow score > or =550, 0.5-mg/ml AA-induced aggregation > or =20%, and 10-micromol/l adenosine diphosphate (ADP)-induced aggregation > or =70%. Thirty patients (6.2%) were found to be aspirin resistant and randomized to receive either low-dose aspirin + omega-3 fatty acids (4 capsules daily) or aspirin 325 mg daily. After 30 days of treatment patients were re-tested.nnnRESULTSnBoth groups (n = 15 each) had similar clinical characteristics. After treatment significant reductions in AA- and ADP-induced aggregation and the VerifyNow score were observed in both groups. Plasma levels of thromboxane B2 were also reduced in both groups (56.8% reduction in the omega-3 fatty acids group, and 39.6% decrease in the aspirin group). Twelve patients (80%) who received omega-3 fatty acids and 11 patients (73%) who received aspirin 325 mg were no longer aspirin resistant after treatment.nnnCONCLUSIONSnTreatment of aspirin-resistant patients by adding omega-3 fatty acids or increasing the aspirin dose seems to improve response to aspirin and effectively reduces platelet reactivity.

Implications of inferior ST-segment depression in anterior acute myocardial infarction: Electrocardiographic and angiographic correlation

This study assesses the significance of inferior ST-segment depression during anterior acute myocardial infarction (AMI) by investigating the relationship between inferior ST-segment depression and (1) the site of the left anterior descending (LAD) coronary artery lesion and (2) ST-segment deviation in the various anterior and lateral leads. We studied 126 patients with anterior AMI who underwent coronary angiography within 21 days of hospitalization. The admission 12-lead electrocardiograms were evaluated for ST-segment amplitude in each lead at 0.08 second after the J-point. Coronary angiography was evaluated for the site and severity of luminal narrowing of the coronary arteries. The site of the culprit lesion in the LAD artery, relative to the origin of the first septal and diagonal branches, was determined. In four patients no lesion was identified in the LAD artery. Of the remaining 122 patients, 40 and 53 patients had a LAD artery lesion proximal to the first septal and first diagonal branches, respectively. Additional luminal narrowing (> or = 70% of diameter) was found in the circumflex and the right coronary arteries in 27 and 37 patients, respectively. ST-segment depression of > 1 mm in leads II, III, and aVF was noted in 24, 29, and 24 patients, respectively. The prevalence of a LAD artery preseptal and prediagonal lesion was higher in patients with inferior ST-segment depression.(ABSTRACT TRUNCATED AT 250 WORDS)

Drug‐eluting stents in bifurcation lesions: To stent one branch or both?

Objectives: The objective of this study was to compare two techniques to treat bifurcation lesions: a single drug‐eluting stent (DES) implanted in the main branch combined with balloon dilatation for the side branch vs. stenting of both branches (double stent). Background: Percutaneous coronary intervention in coronary bifurcation lesions remains challenging. Although DES reduce restenosis in lesions, the double stent procedure has not shown clear advantages over a single stent with balloon dilation. Methods: Fifty‐three symptomatic patients with true bifurcation lesions were treated using either the double stent technique (n = 25) or one stent in the parent vessel plus balloon angioplasty of the side branch (n = 28). Procedural results and major adverse cardiac event rates (MACE: cardiac death, myocardial infarction, target vessel revascularization (TVR)) were compared. Results: Angiographic procedural success (residual stenosis <30% in both branches) was 75% in the single stent group and 100% in the double stent group (P = 0.01). All differences were due to residual stenosis of the side branch. Clinical follow‐up (6–18 months) was available for all patients; 90.5% of patients had a coronary angiography or nuclear stress test. Three patients (11%) in the single stent group and two (8%) in the double stent group had ischemia‐driven TVR (P = NS). Asymptomatic angiographic restenosis (>50% diameter stenosis) in the ostium of the side branch was seen in two patients in the double‐stent group. At 6 months, MACE‐free was comparable between groups (89.3% vs. 88%, P = 0.7). Conclusions: When treating bifurcation lesions with sirolimus‐eluting stents, restenosis following a single stent procedure is comparable to stenting both parent and side branch vessels. Thus, stenting the main‐branch lesion, coupled with balloon angioplasty in the side branch, produces a high success rate and good clinical outcomes at 6 months.

Prognostic significance of maximal precordial St-segment depression in right (V1 to V3) versus left (V4 to V6) leads in patients with inferior wall acute myocardial infarction

This study examines whether patients with inferior wall acute myocardial infarction (AMI) and maximal ST-segment depression in left precordial leads are at higher risk for in-hospital mortality. The charts of patients (n = 213) with inferior wall AMI and an initial electrocardiogram that displayed peaked, tall T waves or ST-segment elevation with upright T waves in inferior leads were reviewed, after excluding patients with inverted T waves in inferior leads (n = 75). ST-segment deviation from baseline was measured for all leads. Patients were classified into 3 types: I = no precordial ST-segment depression; II = sum of ST-segment depression in leads V1 to V3 equal to or more than the sum of ST-segment depression in leads V4 to V6; and III = maximal precordial ST-segment depression in leads V4 to V6. Thirty-six patients (17%) died in the hospital. In-hospital mortality rates for patients with types I and II were 12% and 10%, respectively, compared with 41% for those with type III (p < 0.0001). Mortality rates in surviving patients were similar for all types up to 1 year after infarction. Multivariate logistic regression models for in-hospital mortality by ST-segment depression type adjusted for age, previous AMI, diabetes mellitus, and thrombolytic therapy revealed that type III pattern was a strong predictive factor for in-hospital mortality (odds ratio = 4.9, p = 0.0008, 95% confidence interval 1.93 to 12.26). Thus, patients with inferior wall AMI and maximal precordial ST-segment depression in leads V4 to V6 are at high risk for in-hospital mortality.

Isolated mid-anterior myocardial infarction: a special electrocardiographic sub-type of acute myocardial infarction consisting of ST-elevation in non-consecutive leads and two different morphologic types of ST-depression

UNLABELLEDnWe describe eight patients with a distinct electrocardiographic pattern of anterior wall myocardial infarction characterized by three main features: (1) a pattern of transmural ischemia (ST-elevation with positive T-wave) in non-consecutive leads: a VL and V2, and two different types of ST-depression; (2) a pattern of true reciprocal changes (ST-depression and negative T-wave) in III and a VF; (3) a pattern of sub-endocardial ischemia (ST-depression with positive T-wave) in V4-5, while ST in V3 was either isoelectric or depressed. We characterize the electrocardiographic features and correlate them with the echocardiographic, radionuclide, and angiographic data. All patients admitted to the coronary care unit from January 1990 to April 1992 with evolving acute myocardial infarction were evaluated prospectively. Patients whose admission electrocardiogram met the description above were included. The electrocardiographic evolution, echocardiographic, Technetium MIBI tomography, and coronary angiography are described. Of 471 patients with acute anterior wall myocardial infarction, admitted to the coronary care unit during the study period, eight patients met the inclusion criteria (1.7% of acute anterior wall myocardial infarction). Echocardiographic studies revealed mid-anterior hypokinesis in two patients, anterior and apical hypokinesis in one, and no wall motion abnormality in four patients. Technetium MIBI tomography, done in five patients, was consistent with mid-anterior or midanterolateral infarction without involvement of the septum or apex. Coronary angiography, performed in seven patients, demonstrated significant obstruction of the first diagonal branch in all of the patients. In four patients, the diagonal occlusion was the only significant coronary lesion in the left coronary artery.nnnCONCLUSIONnMost of the anterior myocardial infarctions also involve the septal and apical regions. Anterior wall myocardial infarctions limited to the mid-anterior or mid-anterolateral wall, without apical or septal wall involvement are relatively rare. This study describes a special electrocardiographic form of anterior wall acute myocardial infarction. This distinct electrocardiographic pattern represents true mid-anterior wall myocardial infarction, caused by occlusion of a first diagonal branch of the left anterior descending coronary artery. The septal and apical regions are not involved because the blood supply via the left anterior descending artery is not interrupted.

Circulating endothelial progenitor cell levels and function in patients who experienced late coronary stent thrombosis

AIMSnThe pathogenesis of late coronary stent thrombosis may be related to impaired arterial healing. Endothelial progenitor cells (EPCs) have been shown to play an important role in repair and re-endothelialization following vascular injury. We hypothesized that patients who develop late stent thrombosis may have reduced or dysfunctional EPCs, and aimed to compare EPC level and function in patients who experienced stent thrombosis vs. matched controls.nnnMETHODS AND RESULTSnPatients who developed late (> 30 days) stent thrombosis within the past 3 years were compared with matched patients who underwent stenting and did not develop stent thrombosis. All patients had blood samples taken ≥ 3 months from the stent thrombosis or index procedure. The proportion of peripheral mononuclear cells (PMNCs) expressing vascular endothelial growth factor receptor 2 (VEGFR-2), CD133, and CD34 was evaluated by flow cytometry. Endothelial progenitor cell colony forming units (CFUs) were grown from PMNCs, characterized and counted following 7 days of culture. The two groups (n = 30 each) were well-matched (93.3% men, mean age 60-62 years, 33.3% diabetes, 73-80% DESs). The proportion of cells co-expressing VEGFR-2, CD133, and CD34 was lower in the stent thrombosis group compared with the control [VEGFR-2(+)CD133(+): 0.18% (0.03-0.41%) vs. 0.47% (0.16-0.66%), P = 0.01; VEGFR-2(+)CD34(+): 0.32% (0.22-0.70%) vs. 0.66% (0.24-1.1%), P = 0.03]. The number of EPC CFUs was also lower in the stent thrombosis group [3.9% (3.2-5.5%) vs. 8.3% (6.5-13.4%) colonies/well, respectively, P < 0.0001].nnnCONCLUSIONnPatients who suffered late coronary stent thrombosis appear to have reduced levels of circulating EPCs and impaired functional properties of the cells. These findings require validation by further studies, but may contribute to understanding the pathogenesis of late stent thrombosis.

Use of noninvasive tools in primary pulmonary hypertension to assess the correlation of right ventricular function with functional capacity and to predict outcome

Abstractxa0Most patients with Primary Pulmonary Hypertension (PPH) have severe exertional limitation which ultimately leads to right heart failure and death. The purpose of the study was to assess the correlation between right ventricular (RV) systolic and diastolic noninvasive variables and exercise tolerance, as well as the predictors of adverse outcome in treated patients.MethodsWe prospectively studied 29 patients, 17 with PPH and 12 with PPH due to collagen disease. RV parameters were assessed by echocardiography and Radionuclide ventriculography. Pulmonary function and clinical profile were assessed by 6xa0min walk test and NYHA class. The patients were followed-up during 2xa0years for cardiac death and cardiac deterioration.ResultsMean age was 51xa0±xa015xa0years, 22 (78%) women. NYHA class1 in 2 pts, class 2 in 17, class 3 in 8 and class 4 in 2xa0pts. Pulmonary function (DLCO) was low in 25 (86%) pts, mean 22xa0±xa048%. Six minutes walk distance was 358xa0±xa0132xa0m, RVEF was 34xa0±xa011% (range 16–51%). Among RV variables, RVEF, RA area and TR were independently correlated to 6xa0min walk. Within follow up of 2xa0years, there were 10 patients with adverse outcome (4 deaths and 6 deteriorated to NYHA class 3 and 4). Among all clinical and noninvasive variables, RVEF only was correlated to adverse outcome.ConclusionThe noninvasive tests of RVEF, RA size and TR were closely correlated to exercise tolerance. However, among the various clinical, functional and RV variables, RVEF was the only variable correlated with adverse outcome in pts with PPH.

Coronary stent deployment without predilation in acute myocardial infarction : A feasible, safe, and effective technique

Direct percutaneous transcatheter revascularization (PTCR) is becoming an acceptable therapy for acute myocardial infarction (AMI). Stenting in the setting of AMI, once consid ered contraindicated, is emerging as a suitable option in this situation. Coronary stenting without predilation (SWOP) may potentially shorten the procedure and radiation time, reduce costs, and decrease procedural complications such as coronary dissection and distal embolization. It is expected to cause less vascular injury, with a reduction in the rate of in-stent restenosis. In this preliminary study the authors evaluated the feasibility of the SWOP procedure in 22 selected patients with AMI. Indications for catheter-based myocardial reperfusion were the following: extensive anterior wall MI (68%), inferior wall and right ventricular MI (23%), and inferior wall MI with contraindication for thrombolytic therapy (9%). Patients with cardiogenic shock or with contraindications for aspirin or ticlopidine were excluded. SWOP was successful in 21 attempts (95%), and final procedural success was achieved in all. Proximal or distal dissections were seen in three cases and were treated by additional three stents. Thrombolysis in myocardial infarction (TIMI) flow 3 was restored in all patients. There were no distal embolizations, side branch occlusions, coronary perforations, procedure-related emergency bypass operations, or deaths. It is concluded that in selected patients with AMI, coronary artery stenting without predilation is feasible and safe and does not introduce additional risk to the patients.