Q-wave Myocardial Infarction Research Articles

Role of right-sided chest leads in the detection of multivessel coronary artery disease in patients with extended Q-wave anterior myocardial infarction

To evaluate the improvement of diagnostic ability of exercise testing to detect multivessel coronary artery disease in patients with extended Q-wave anterior myocardial infarction, using additional right-sided chest leads. Fifty-two consecutive patients with Q-wave anterior myocardial infarction underwent exercise testing, using the standard 12 and the additional right-sided (V3R, V4R, V5R) chest leads, thallium-201 scintigraphy and coronary arteriography. Twenty-one (40%) patients had one-vessel disease, 18 (35%) had two-vessel disease and 13 (25%) had three-vessel disease. The sensitivities of the standard 12-lead exercise testing and its combination with the additional right-sided chest leads were 24% (5/21) versus 28% (6/21) for the detection of one-vessel disease (P: NS), 33% (6/18) versus 83% (15/18) for the detection of two-vessel disease (P<0.05) and 38% (5/13) versus 92% (12/13) for the detection of three-vessel disease (P<0.05), respectively. In thallium-201 scintigraphy, 29 of the 31 (94%) patients with multivessel coronary artery disease demonstrated reversible ischemia. The usual 12-lead exercise testing could detect ischemia in 11 (35%) of these 31 patients, while the addition of the right-sided chest leads could detect ischemia in 27 (87%) of them (P<0.05). The additional right-sided chest leads significantly improve the low sensitivity of the usual exercise testing to detect multivessel coronary artery disease in patients with previous extended Q-wave anterior myocardial infarction.

A comparison of bivalirudin to heparin with protamine reversal in patients undergoing cardiac surgery with cardiopulmonary bypass: The EVOLUTION-ON study

Unfractionated heparin and its antidote, protamine sulfate, allow for rapid and reversible anticoagulation during cardiac surgery with cardiopulmonary bypass, yet limitations exist, including a variable dose-response, dependence on a cofactor for anticoagulant effect, and antigenic potential. This trial was performed to evaluate the safety and efficacy of bivalirudin as an alternative to heparin with protamine reversal in on-pump cardiac surgery. We conducted a randomized, open-label, multicenter trial comparing heparin with protamine reversal to bivalirudin in patients undergoing cardiac surgery with cardiopulmonary bypass. The primary objective was to demonstrate comparable rates of in-hospital procedural success defined as freedom from death, Q-wave myocardial infarction, stroke, or repeat revascularization. Twenty-one institutions enrolled 101 patients randomized to bivalirudin and 49 patients to heparin treatment. The primary end point of procedural success was not significantly different between the bivalirudin arm and the heparin/protamine arms at 7 days, 30 days, or 12 weeks' follow-up. Adequate anticoagulation was achieved in all patients. Secondary end points including mortality, 24-hour blood loss, overall incidence of transfusions, and duration of surgery were similar between the two arms. Bivalirudin is a safe and effective anticoagulant for patients undergoing a wide range of cardiac surgical procedures with cardiopulmonary bypass. Procedural success rates with bivalirudin were similar to rates in patients receiving heparin anticoagulation, with no difference in mortality. Avoidance of blood stasis and attention to the intraoperative medical management of patients is critical for successful use of bivalirudin during cardiopulmonary bypass.

Invited commentary

After surviving earlier attacks on its efficacy through the conduct of well-designed randomized trials, carotid endarterectomy (CEA) is again being challenged by the purported “less-invasive” alternative of carotid artery stenting (CAS). The study by Stoner et al provides important data for the current debate but has limitations that leave many questions unanswered. The SAPPHIRE trial injected the issue of cardiac morbidity into the CEA vs CAS debate. Perioperative cardiac events can be compared between studies only if similar, standardized protocols are used for surveillance for myocardial damage. Unfortunately, the National Surgical Quality Improvement Program database includes only Q-wave myocardial infarction (a small subset of all perioperative myocardial infarctions). However, the observation in this study that local or regional anesthesia was associated with better outcomes at least raises the question of whether the differences in cardiac morbidity seen in the SAPPHIRE trial were anesthetic rather than procedure related. An important issue often neglected in the CEA vs CAS debate is whether neurologically asymptomatic, medically high-risk patients are likely to benefit from either procedure. The relatively benign natural history of asymptomatic carotid stenosis established in the Asymptomatic Carotid Atherosclerosis Study trial should not be forgotten. The limitations of the National Surgical Quality Improvement Program database with regard to the collection of specific cardiac risk factors such as prior myocardial infarction or the presence of angina limit the usefulness of this study in guiding the selection of neurologically asymptomatic patients who are more likely to benefit from CEA. Many of the risk factors identified in this study (diabetes, age, and smoking) are surrogate markers for coronary artery disease. A specific cardiac history combined with noninvasive cardiac screening of selected individuals is likely a more important risk assessment approach for the practicing surgeon than using the risk factors identified in this study alone. Clinical studies like this one are as important as randomized trials in establishing the efficacy of procedures. Community-wide studies are necessary to demonstrate that the procedural outcomes observed in a randomized trial can be achieved across the entire spectrum of patients likely to undergo the procedure and physicians likely to perform the procedure. This study adds to the literature that supports the fact that CEA can be performed across this spectrum with perioperative adverse event rates comparable to those achieved in the randomized trials. It remains to be seen whether this will be as true for CAS as it is for CEA.

Sirolimus‐ versus Paclitaxel‐Eluting Stents: A Comparison of Two Consecutive Series in Routine Clinical Practice

We compared two consecutive series of patients treated with sirolimus-eluting stents (SES) or paclitaxel-eluting stents (PES). Two hundred and ninety-five patients with 590 coronary lesions were treated with 274 SES and 379 PES. Patients with symptoms or positive dobutamine stress echocardiography were subjected to repeat coronary angiography. During a follow-up of 13.3 +/- 5.7 months, the incidence rate of major adverse cardiac events (MACE) was 4.1%, including, 1 death, 4 Q-wave myocardial infarctions, 2 late angiographic stent thromboses, 3 subacute stent thromboses, and 11 target vessel revascularizations (TVR), and was not significantly different between SES (n = 5) and PES (n = 7). Stent overlapping was found to be an independent predictor of both MACE (odds ratio = 0.078, P = 0.02) and TVR (odds ratio = 0.077, P = 0.02). Follow-up symptoms- or ischemia-driven angiography was performed in 45 patients. Only vessel size was a predictor of stent restenosis (P = 0.02), independent of stent type. Late loss was independently predicted by postdilatation of stent (beta =-0.24, P = 0.03), but not by type of stent (P = 0.14) or other parameters. Edge restenosis was seen in 8 patients subjected to lesion predilatation. The restenosis pattern after SES implantation was focal, but diffuse (n = 1) or proliferative (n = 1) restenosis, and in-stent aneurysm formation (n = 1) was also seen with PES. Despite a trend for a higher incidence of MACE with PES, no significant differences between the two stent types were detected. Diffuse restenosis was seen only with PES, and edge restenosis only in lesions with balloon predilatation before stent implantation. Stent overlapping was an independent predictor of both TVR and MACE.

Electrocardiography in Women

In the just over 100 years since the first ECG was performed,1 the ECG has become the most extensively used noninvasive diagnostic and prognostic tool in cardiology. Used both at rest and during provocative exercise, the 12-lead ECG has impressive, if imperfect, utility for rhythm analysis, detection of ischemic and hypertrophic heart disease, and outcome prediction in a variety of clinical settings, with a large body of literature that illustrates and supports these applications. The first observation of gender differences in the ECG was published 85 years ago by Bazett,2 demonstrating that women have significantly longer QT intervals than men despite having higher heart rates. However, despite a growing body of literature demonstrating significant gender differences in QRS amplitudes and duration,3–6 QT intervals,5,7,8 ST-segment deviation,9,10 and novel, computer-based measurements of T-wave complexity,8,11 few ECG criteria routinely use gender-specific diagnostic criteria, and there has been a relative paucity of data on the prognostic performance of ECG variables in women. Articles pp 473 and 481 Two studies in the current issue of Circulation by Rautaharju and colleagues12,13 provide a wealth of new findings and impetus for further study of the ECG in women. Using well-validated computerized ECG methodology, the authors examined the value of a number of ECG variables for predicting incident coronary heart disease and its mortality, incident congestive heart failure, and total mortality in more than 38 000 women participating in the dietary modification trial of the Women’s Health Initiative. Although both studies reconfirm the predictive value of ECG evidence of prior Q-wave myocardial infarction (MI), the principle new findings are the strong predictive value of various ECG measures of repolarization, and in particular of the QRS/T angle,12,13 a measure of the spatial angle between mean QRS and T vectors. In the …

Age-related differences in the management and outcome of patients with acute coronary syndromes

Age-related differences in patients with an acute coronary syndrome (ACS) have not been well characterized in prior observational studies that often included only certain age groups or subjects with myocardial infarction (MI). We stratified 4627 patients admitted with an ACS across 9 provinces between 1999 and 2001 enrolled in the Canadian ACS Registry into 3 age groups (< 65, 65-74, and > or = 75 years) to evaluate differences in clinical characteristics, management, and 1-year outcome. Older patients more frequently had previous angina, MI, or heart failure and were less likely to have positive cardiac markers, ST elevation, and Q-wave MI or to receive thrombolytics, beta-blockers, and cholesterol-lowering and antiplatelet agents in hospital, at discharge, and at 1 year. In multivariable analyses controlling for patient factors, every decade increase in age was independently associated with reduced use of coronary angiography (odds ratio [OR] 0.79, 95% CI 0.74-0.84, P < .001) and percutaneous coronary intervention (OR 0.88, 95% CI 0.81-0.95, P = .001). When adjusted for validated clinical prognosticators and differences in management, every decade of age increment independently predicted an increased risk of death at 1 year (OR 1.87, 95% CI 1.66-2.12, P < .001). Across the broad spectrum of ACS, elderly patients had more complex comorbidities and worse outcome, yet they were less likely to undergo revascularization or to receive acute and long-term evidence-based medications. Our findings emphasize the ongoing need to better define and promote optimal therapeutic regimens for elderly patients with ACS.

Inhibition of complement activation by pexelizumab reduces death in patients undergoing combined aortic valve replacement and coronary artery bypass surgery

We sought to evaluate the effects of pexelizumab, a C5 complement inhibitor, on death and myocardial infarction in patients undergoing combined aortic valve replacement and coronary artery bypass grafting surgery. The Pexelizumab for Reduction in Myocardial Infarction and Mortality in Coronary Artery Bypass Graft surgery trial, a phase III prospective, randomized, double-blind, placebo-controlled study, enrolled 3099 patients at 205 centers. The primary end point was the composite of death, myocardial infarction, or both at postoperative day 30 in patients undergoing coronary artery bypass grafting without valve surgery. Postoperative myocardial infarction was defined as a creatine kinase MB fraction value of 100 ng/mL or greater, Q-wave myocardial infarction with a creatine kinase MB fraction value of 70 ng/mL or greater, or new Q-wave evidence of myocardial infarction by postoperative day 30. Because patients undergoing coronary artery bypass grafting with a valve procedure were not included in the primary population, separate analysis of death and myocardial infarction was conducted in 218 patients undergoing combined aortic valve replacement and coronary artery bypass grafting surgery. Of the 353 patients randomized to any valve procedure, 106 (61%) underwent combined aortic valve replacement and coronary artery bypass grafting in the pexelizumab treatment group compared with 112 (63%) patients in the placebo group. Coronary artery bypass grafting was performed with 1 or more internal thoracic artery grafts in 139 (64%) patients and with 1 or more saphenous vein grafts in 179 (82%) patients. There were 4 (3.8%) deaths in the pexelizumab group versus 11 (9.9%) in the placebo group by postoperative day 30 and 6 (5.7%) deaths in the active group versus 16 (14.4%) in the placebo group by postoperative day 180 (P =.107 and P =.043, respectively, Fisher exact test). The incidence of myocardial infarction 30 days after surgical intervention was identical in the 2 groups, but the study was not designed to detect differences in this cohort of patients. Inhibition of complement activation by pexelizumab resulted in a decreased mortality at 180 days among 218 patients who underwent combined aortic valve replacement and coronary artery bypass grafting surgery. Additional studies are warranted to confirm this decrease in mortality with pexelizumab in combined aortic valve replacement and coronary artery bypass grafting procedures.

Impact of Three or More Versus a Single Sirolimus-Eluting Stent on Outcomes in Patients Who Undergo Percutaneous Coronary Intervention

This retrospective analysis compared clinical outcomes of patients who underwent stenting with > or =3 sirolimus-eluting stents (SESs) with those who received a single SES. SES (Cypher) implantation for single vessels is proved to be effective and durable, but knowledge regarding the safety and effectiveness of multiple stenting with SESs is currently limited. In total, 929 consecutive patients who received SESs were identified; 63 received > or =3 SESs (multi group) and 866 received 1 SES (single group). The multi group had more non-Q-wave myocardial infarctions (MIs) during the index hospitalization (p = 0.02). At 30-day follow-up, death, Q-wave MI, subacute thrombosis, and major adverse cardiac events were higher in the multi group than in the single group. At 6 months, death, Q-wave MI, target lesion revascularization, and major adverse cardiac events continued to be higher in the multi group. Using multivariate analysis, > or =3 SES implantations, American College of Cardiology/American Heart Association type C lesions, and cardiogenic shock were identified as independent predictors for 6-month major adverse cardiac events. In addition, patients in the multi group had a significantly lower survival rate than patients in the single group (p <0.0001). Patients who required > or =3 SES implantations developed increased periprocedural non-Q-wave MI and worse adverse clinical outcomes at 30 days and 6 months compared with patients who required a single SES implantation. In conclusion, when patients present with multiple coronary lesions, percutaneous coronary intervention with multiple SESs should be undertaken with great caution.

Distal embolic protection during percutaneous coronary intervention in patients with acute coronary syndromes: The RUBY study

To assess the safety and feasibility of the GuardWire system as an embolic protection device during percutaneous coronary intervention (PCI) in acute coronary syndromes (ACS). Distal embolization occurs in approximately 15% of patients after primary angioplasty and is associated with reduced myocardial reperfusion, more extensive myocardial damage and a poor prognosis. Distal embolic protection could reduce the rate of embolic complications and improve outcome. 329 patients (mean age 60+/-12 years) were included: 278 (84.5%) with ST-elevation myocardial infarction (STEMI), 50 (15.2%) with unstable angina/non-STEMI and 1 (0.3%) with post-infarction angina. Primary endpoint was the incidence of major adverse cardiac events (MACE) at 30 days. Secondary endpoints were the magnitude of ST-segment resolution at 90 and 180 min post-procedure, myocardial blush grade, and angiographically visible distal emboli. The GuardWire system was successfully positioned in 99% of patients. Complete ST-elevation resolution (>70%) was observed in 28.5% immediately post-procedure, and in 35.4% and 41.6% at 90 and 180 min post-procedure. TIMI-3 flow grade was achieved by 89.8% of patients after intervention and mean corrected TIMI frame count was 20.2+/-13.2. Grade-3 myocardial blush was seen in 47.7% of patients and distal emboli were angiographically visible in 7.4%. Incidence of MACE at 30 days was 3.3% (death 1.2%; Q-wave MI 0.3%; non-Q-wave MI 0.3%; coronary artery bypass graft 0.6%; repeat PCI 0.9%). The GuardWire system was successfully positioned in nearly all patients without complications. The use of this embolic protection device in ACS patients undergoing PCI was associated with low rates of distal embolization and 30-day MACE.

Persistent and proximal migration of a large coronary thrombus during percutaneous coronary intervention in the setting of acute Q-wave myocardial infarction

We describe a patient with an acute inferior myocardial infarction. Patient was taken to the cardiac catheterization laboratory for primary angioplasty. Angiography revealed 100% occluded proximal right coronary artery (RCA). After initial balloon angioplasty of the occluded RCA, a very large mobile thrombus was seen in the proximal RCA. Despite multiple stenting, suctioning through the guide catheter lumen, and intracoronary thrombolytic therapy, the thrombus persisted and migrated proximally after each stenting. However, patient did well despite of persistent large thrombus burden in the proximal RCA on aggressive antithrombotic treatment.

Concordance of Electrocardiographic Patterns and Healed Myocardial Infarction Location Detected by Cardiovascular Magnetic Resonance

Q-wave myocardial infarction (MI) location is generally based on a pathologic correlation first proposed >50 years ago. Despite the proved reliability of contrast-enhanced cardiovascular magnetic resonance (CE-CMR) imaging to detect and locate infarcted areas, no global study has been conducted with the aim of correlating the electrocardiographic (ECG) patterns of Q-wave MI with infarct location. We studied this correlation in 51 patients with ST-elevation acute coronary syndrome who presented with Q waves or equivalents during MI. Seven preestablished ECG patterns that matched with high specificity to 7 different MI locations as detected by CE-CMR imaging were used to assess its value in clinical practice to locate an infarcted area. There were 4 ECG patterns in the anteroseptal zone (23 patients; septal, apical, and/or anteroseptal, extensive anterior, and limited anterolateral) and 3 ECG patterns in the inferolateral zone (28 patients; lateral, inferior, and inferolateral). In conclusion, (1) the predefined ECG patterns we used matched well (86% global concordance) with their corresponding infarction areas as detected by CE-CMR imaging and have real value in clinical practice, and (2) the RS morphology in lead V(1) is due to lateral MI and the QS morphology in lead aVL is due to mid-anterior and mid-lateral MI. Therefore, the terms posterior and high lateral infarction are incorrect and should be changed to lateral wall and limited anterolateral wall MI.

Phase-Sensitive Inversion-Recovery MR Imaging in the Detection of Myocardial Infarction

To prospectively determine if phase-sensitive inversion-recovery (IR) magnetic resonance (MR) imaging eliminates the need to find the precise inversion time (TI) to null the signal of normal myocardium to achieve high contrast between infarcted and normal myocardium. Informed consent was obtained from each patient for this prospective MR imaging research study, which was approved by the institutional review board. Twenty patients (16 men; four women; mean age, 56 years +/- 12.3) who experienced Q-wave myocardial infarction 2 weeks earlier were examined with a 1.5-T MR system 10 minutes after administration of 0.1 mmol per kilogram of body weight gadobenate dimeglumine. To determine the optimal TI, a TI scout sequence was used. A segmented two-dimensional IR turbo fast low-angle shot (FLASH) sequence and a segmented two-dimensional IR true fast imaging with steady-state precession (FISP) sequence that produces both phase-sensitive and magnitude-reconstructed images were used at TI values of 200-600 msec (TI values were varied in 100-msec steps) and at optimal TI (mean value, 330 msec). Contrast-to-noise ratios (CNRs) of normal and infarcted myocardium and the area of infarcted myocardium were determined. Magnitude-reconstructed IR turbo FLASH images were compared with magnitude-reconstructed and phase-sensitive IR true FISP images. Two-tailed unpaired sample Student t test was used to compare CNRs, and two-tailed paired-sample Student t test was used to compare area of infarction. Mean CNR of images acquired with IR turbo FLASH and IR true FISP (phase-sensitive and magnitude-reconstructed images) at optimal TI (mean value, 330 msec) were 6.6, 6.2, and 6.1, respectively. For a TI of 200 msec, CNR values were -4.3, -4.0, and 7.2, respectively; for TI of 600 msec, CNR values were 3.1, 3.3, and 4.3, respectively. Area of infarcted myocardium was underestimated on magnitude-reconstruction images (P = .002-.03) for short TI values (ie, 200 msec) for both sequences and for a TI of 300 msec for IR true FISP but not on phase-sensitive reconstructed IR true FISP images when compared with IR turbo FLASH images obtained at optimal TI. Phase-sensitive image reconstruction results in reduced need for precise choice of TI and more consistent image quality.

Directional atherectomy before stenting versus stenting alone in percutaneous coronary interventions: A meta-analysis

Plaque debulking before stenting is still controversial. We performed a meta-analysis of 12 randomized and non-randomized trials comparing directional coronary atherectomy (DCA) before stenting versus stenting alone. Angiographic end points were acute gain, late loss and angiographic restenosis rate. Clinical end points were early major adverse cardiac events [MACEs: death, Q-wave myocardial infarction (MI), non-Q-wave MI], late MACEs (death, Q-wave MI) and target lesion revascularization (TLR). Data are expressed as odds ratio (OR) with 95% confidence intervals (CI) or weighted mean difference (WMD) with 95% CI, as appropriate. A total of 1216 patients undergoing DCA before stent and 1484 patients undergoing stent alone have been included. DCA before stent was associated to a better acute gain compared to stenting alone (WMD 0.23, [0.18–0.28]; p < 0.0001), to a striking reduction of angiographic restenosis rate (OR of 0.67, [0.54–0.84], p = 0.0003) and to a significantly lower rate of late TLR (OR 0.73 [0.59–0.91], p = 0.006). Late loss did not differ between the two groups (WMD 0.00 [− 0.08 and 0.08], p = 0.98). We found a higher rate of early MACEs for the combined approach (OR 1.87 [1.16–3.02], p = 0.01), with similar prevalence of late MACEs (OR 0.83 [0.65–1.06], p = 0.13). In conclusion, this meta-analysis demonstrates that DCA before stenting is superior to stenting alone with regard to acute angiographic results and TLR with a similar prevalence of late MACEs. The higher prevalence of early MACEs with DCA before stenting, however, is disturbing and probably related to distal embolization.

Efficacy of Sirolimus-Eluting Stents Compared With Bare Metal Stents for Saphenous Vein Graft Intervention

Saphenous vein graft (SVG) intervention is associated with a significantly increased rate of periprocedural complications and late clinical and angiographic restenosis. We examined the efficacy and safety of sirolimus-eluting stents (SESs; Cypher) compared with bare metal stents (BMSs) in SVG intervention. Forty-eight patients who had 50 SVG lesions and underwent standard percutaneous coronary intervention with SESs (SES group) were compared with 57 patients who had 64 SVG lesions and underwent intervention with BMSs (BMS group). All patients received distal protection devices during SVG intervention. In-hospital, 30-day, 6-month, and 1-year clinical outcomes in the 2 groups were compared. Baseline clinical and procedural characteristics were balanced between groups. There were no deaths or Q-wave myocardial infarctions during the index hospitalization, but compared with the BMS group, patients in the SES group had significantly fewer non-Q-wave myocardial infarctions (4% vs 21%, p = 0.01), which was mainly attributed to increased periprocedural creatine kinase-MB levels. At 30-day, 6-month, and 1-year follow-ups, all clinical outcomes were similar between groups. Event-free survival at 1 year was also similar between groups (p = 0.84). In conclusion, the use of SESs in patients who undergo SVG intervention with a distal protection device is clinically safe and feasible but is not associated with decreased clinical events up to 1 year compared with BMSs.

“Full metal jacket” (stented length ≥64 mm) using drug-eluting stents for de novo coronary artery lesions

Stented segment length was a predictive factor for restenosis in the bare metal stent era. The objective of the study was to evaluate the medium-term clinical outcome and the potential for adverse effects when very long segments (ie, > or =64 mm of stented length) are treated by drug-eluting stent (DES) implantation, an approach colloquially referred to as a "full metal jacket." Since April 2002, we have used DES as the default stent for all percutaneous coronary interventions. From our prospective institutional database we identified 122 consecutive patients, with de novo coronary lesions, in whom a coronary artery was treated with at least 64 mm of overlapping DES: 81 patients were treated with sirolimus-eluting stents and 41 with paclitaxel-eluting stents. The mean number of stents per lesion was 3.3 +/- 1.1, and the median stented length was 79 mm (range 64-168 mm). Periprocedural Q-wave myocardial infarction (MI) occurred in 2 patients (1.6%) and subacute stent thrombosis in 1 patient (0.8%). During 1-year follow-up, 5 patients (4.1%), including 3 patients treated for acute MI with cardiogenic shock, died and 10 patients (8.2%) had nonfatal MI (creatine kinase-MB >3 times). The 1-year target vessel revascularization rate was 7.5% and the overall incidence of major adverse cardiac events was 18%. Outcomes in sirolimus-eluting stents and paclitaxel-eluting stents groups did not differ statistically. The use of DES for the treatment of diffuse lesions was associated with a low rate of repeat revascularization, irrespective of stent type. No safety concerns were raised at medium-term follow-up.

Platelet Nitric Oxide Responsiveness

Nitric oxide (NO) is critically important in the regulation of vascular tone and the inhibition of platelet aggregation. We have shown previously that patients with acute coronary syndromes (ACS) or stable angina pectoris have impaired platelet responses to NO donors when compared with normal subjects. We tested the hypotheses that platelet hyporesponsiveness to NO is a predictor of (1) cardiovascular readmission and/or death and (2) all-cause mortality in patients with ACS (unstable angina pectoris or non-Q-wave myocardial infarction). Patients (n=51) with ACS had evaluation of platelet aggregation within 24 hours of coronary care unit admission using impedance aggregometry. Patients were categorized as having "normal" (> or =32% inhibition of ADP-induced aggregation with the NO donor sodium nitroprusside; 10 micromol/L; n=18) or "impaired" (<32% inhibition of ADP-induced aggregation; n=33) NO responses. We then compared the incidence of cardiovascular readmission and death during a median of 7 years of follow-up in these 2 groups. Using a Cox proportional hazards model adjusting for age, sex, index event, postdischarge medical treatment, revascularization status, left ventricular systolic dysfunction, concurrent disease states, and cardiac risk factors, impaired NO responsiveness was associated with an increased risk of the combination of cardiovascular readmission and/or death (relative risk, 2.7; 95% CI, 1.03 to 7.10; P=0.041) and all-cause mortality (relative risk, 6.3; 95% CI, 1.09 to 36.7; P=0.033). Impaired platelet NO responsiveness is a novel, independent predictor of increased mortality and cardiovascular morbidity in patients with high-risk ACS.

Diabetes mellitus: clinical presentation and outcome in men and women with acute coronary syndromes. Data from the Euro Heart Survey ACS

To study clinical presentation, in-hospital course and short-term prognosis in men and women with diabetes mellitus and acute coronary syndromes (ACS). Men (n = 6488, 21.2% with diabetes) and 2809 women (28.7% with diabetes) < or = 80 years old, with a discharge diagnosis of ACS were prospectively enrolled in the Euro Heart Survey of ACS. Women with diabetes were more likely to present with ST elevation than non-diabetic women, a difference that became more marked after adjustment for differences in smoking, hypertension, obesity, medication and prior disease [adjusted odds ratio (OR) 1.46 (1.20, 1.78)], whereas there was little difference between diabetic and non-diabetic men [adjusted OR 0.99 (0.86, 1.14)]. In addition, women with diabetes were more likely to develop Q-wave myocardial infarction (MI) than non-diabetic women [adjusted OR 1.61 (1.30, 1.99)], while there was no difference between men with and without diabetes [adjusted OR 0.99 (0.85, 1.15)]. There were significant interactions between sex, diabetes and presenting with ST-elevation ACS (P < 0.001), and Q-wave MI (P < 0.001), respectively. Of the women with diabetes, 7.4% died in hospital, compared with 3.6% of non-diabetic women [adjusted OR 2.13 (1.39, 3.26)], whereas corresponding mortality rates in men with and without diabetes were 4.1% and 3.3%, respectively [OR 1.13 (0.76, 1.67)] (P for diabetes-sex interaction 0.021). In women with ACS, diabetes is associated with higher risk of presenting with ST-elevation ACS, developing Q-wave MI, and of in-hospital mortality, whereas in men with ACS diabetes is not significantly associated with increased risk of either. These findings suggest a differential effect of diabetes on the pathophysiology of ACS based on the patient's sex.

Postexercise VO 2 “Hump” phenomenon as an indicator for inducible myocardial ischemia in patients with acute anterior myocardial infarction

Objectives At exercise testing with respiratory gas analysis in patients with inducible myocardial ischemia, we have occasionally observed abnormal transient oxygen uptake (VO 2) components with a characteristic “Hump”-shaped morphology early after exercise, which may serve as an index for inducible ischemia. We examined this hypothesis in patients with anterior q-wave myocardial infarction in whom the accuracy to identify ischemia by exercise ECG is limited. Design From patients with acute anterior q-wave infarction but without clinically overt heart failure who underwent pre-discharge exercise testing, we examined patients with (Group-I, n = 30) and without (Group-N, n = 29) inducible ischemia. To identify “Hump”, postexercise VO 2 (up to 4 min) standardized for peak VO 2 was exponentially fitted with use of peak VO 2 and VO 2 of 90–240 s, yielding “expected VO 2”. “D-curve” was obtained by subtracting “expected VO 2” from measured VO 2. Results Although exercise-induced ST depressions more frequently appeared in Group-I (27%) than in Group-N (3%, p < 0.05), the prevalence was low. D-curve peaked later ( p < 0.01) and its value was greater ( p < 0.05) in Group-I than in Group-N. When “Hump” was defined to be present if D-curve peaked ≥ 40 s and its peak value ≥ 15%, it was far more frequently found in Group-I ( n = 17 / 30) than in Group-N ( n = 1 / 29, p < 0.01). Thus, “Hump” could diagnose inducible ischemia with a sensitivity of 57% and a specificity of 97%. Conclusions Although not highly sensitive, postexercise VO 2 “Hump” with its peak occurring around 60 s after exercise is a specific marker for inducible ischemia. The identification may be useful, particularly in patients with limited accuracy of exercise ECG such as those with q-wave anterior infarction.

Prognostic Value of Viable Myocardium in Patients with Non-Q-wave and Q-wave Myocardial Infarction

This study assessed the amount and prognostic value of myocardial viability in patients with non-Q-wave myocardial infarction (NQMI) and Q-wave myocardial infarction (QMI). A total of 175 patients with MI and an ejection fraction < or = 45% underwent dobutamine stress echocardiography. On the basis of clinical criteria and myocardial viability, 110 patients were revascularized. The amount of viable myocardium and the clinical outcome were compared in the NQMI and QMI groups. Patients with NQMI exhibited a larger amount of viable myocardium compared with those with QMI. The mortality rate was 6% in patients with NQMI with viable myocardium and subsequent revascularization, 33% in patients with NQMI without viable myocardium or revascularization, 27% in patients with QMI with viable myocardium and subsequent revascularization, and 33% in patients with QMI without viable myocardium or revascularization. In conclusion, our data suggest that patients with NQMI and viable myocardium have the best prognosis after revascularization.

Impact of Treatment of Coronary Artery Disease With Sirolimus-Eluting Stents on Outcomes of Diabetic and Nondiabetic Patients

Patients with diabetes mellitus are at increased risk for repeat interventions and mortality after coronary angioplasty and stenting. The efficacy of sirolimus-eluting stents (SESs) to improve the outcomes of these patients is a focus of interest. In the first 1,407 patients treated with SESs at our institution, 492 were diabetic (insulin dependent diabetes mellitus [IDDM], n = 160 and non-insulin-dependent DM [NIDDM], n = 332). The in-hospital and 1- and 6-month clinical outcomes were compared with those of 915 patients without DM (non-DM). The baseline characteristics were similar, except for more women, obesity, previous myocardial infarction, coronary artery bypass grafting, and renal insufficiency in the DM group (p <0.001). Compared with non-DM patients, DM patients had higher in-hospital (p <0.05) and 1-month mortality (p = 0.02). IDDM patients had more in-hospital renal failure (p = 0.04) and Q-wave myocardial infarctions (1.6% vs 0%, p = 0.04) compared with NIDDM patients, and higher mortality (3.1% vs 0.8%, p = 0.04) and subacute stent thromboses (2.3% vs 0.5%, p = 0.07) than non-DM patients at 30 days. At 6 months, DM patients had a higher incidence of Q-wave myocardial infarction, target lesion revascularization-major adverse cardiac events, and composite of death and Q-wave myocardial infarction than non-DM patients (6.0% vs 2.7%, p = 0.01). Late outcomes between the IDDM and NIDDM groups were similar. Multivariate analysis showed diabetes and acute renal failure as independent predictors of target lesion revascularization-major adverse cardiac events. In conclusion, our data showed that, despite a reduction in repeat revascularization, coronary intervention with SESs in diabetic patients is limited by higher mortality at 1 month and a higher incidence of Q-wave myocardial infarction and target lesion revascularization-major adverse cardiac events at 6 months compared with non-DM patients. Careful surveillance is required in IDDM patients undergoing SES implantation.