non-Q Wave Myocardial Infarction Research Articles

Immediate and six months clinical and angiographic results of intracoronary Ephesos stent implantation: the “Ephesos-1” study

Background — This study was conducted to evaluate the clinical and angiographic results of the Ephesos stent implantation in patients with symptomatic coronary artery disease. The Ephesos stent is a new balloon-expandable, stainless steel, tubular stent with multicellular design.Methods — One hundred ten patients with native coronary artery disease were included in the study. The Ephesos stents were implanted in 163 de novo lesions detected in these patients. Immediate and long-term clinical and angiographic follow-up results were evaluated.Results — Most of the patients had unstable angina 63.6%, and 36.7 % of the lesions were type B and C. Mean lesion length was 12.7 ± 4.7. In 62% of the patients the reference lumen diameter was < 3 mm. One Q-wave and one non-Q-wave myocardial infarction (MI) occurred due to acute thrombotic occlusion during hospital stay. The 6-month event-free survival rate was 77.3%. No patients died in the six-month follow-up period, but 2 patients had non-Q wave MI and 1 patient experienced Q-wave MI within this period. Control angiographic data was collected from 110 patients (100% of patients and a total of 163 lesions). Angiographic restenosis rate was 18.1%. Twentytwo patients with restenosis had repeated target lesion balloon dilatation.Conclusion — The results of the present study showed that the Ephesos stent is a safe and effective choice with a low incidence of major adverse cardiac events and restenosis rate within six months of follow-up.

Complement activation in acute coronary syndromes

The complement system is part of the host defence response. However, considerable evidence suggests that complement plays an important role in the pathophysiology of ischemic heart disease. The aim of this study was to evaluate complement activation in patients with all forms of acute coronary syndromes (ACS) and to examine the relationship between the degree of complement activation and myocardial injury. The study population included 152 subjects (26 females): 82 with ACS (35 acute myocardial infarction (AMI), 22 non-Q wave MI (NQMI), 25 unstable angina (UAP)) (Group A), 35 stable angina (SA) (Group B), and 35 healty control subjects (Group C). Complement 3 (C3), Complement 4 (C4), C-reactive protein (CRP), troponin I (TnI) as well as creatine kinase MB (CK-MB) were evaluated. Patients' blood samples were taken on admission (day 1) and after 2, 3 and 7 days in group A. However, only one measurement was performed in the groups B and C. Plasma C3 and C4 peak levels were significantly higher in patients with AMI (141+/-29 and 35+/-11 mg/dl) and NQMI (136+/-13 and 35+/-7 mg/dl) than in patients with SA (128+/-14 and 27+/-10 mg/dl) and the control subjects (114+/-22 and 22+/-7 mg/dl) (p<0.03). Also, C3 and C4 serum levels in patients with SA and UAP (126+/-16 and 31+/-7 mg/dl) were significantly higher than those in control subjects (p<0.01, p<0.03, respectively). At 1-week follow-up, there were no significant differences between the plasma levels of C3 and C4 in patients with UAP (p>0.05). However, plasma levels of C3 and C4 were significantly different between days in patients with AMI and NQMI (p<0.0001). Plasma C3 and C4 levels in ACS showed a relationship with peak CK-MB and Tn I levels (p<0.01). Plasma CRP level in ACS showed positive correlation with C3 (p<0.01) and C4 (p<0.001). In this study, we determined that plasma C3 and C4 levels were elevated in ACS and SA. Although C3 and C4 were higher in ACS and SA, the systemic levels of inflammatory markers in patients with SA and UAP were lower than those found in the AMI and NQMI groups. The relationship between C3, C4 levels and ACS further suggests that the complement activation is related to necrosis within the myocardium.

Serial Angiographic Follow-up Beyond 10 Years After Coronary Artery Bypass Grafting

The long-term prognosis and serial angiographic follow-up beyond 10 years in patients who underwent coronary artery bypass grafting (CABG) have not been fully studied in Japan. In the present study data from 71 patients who underwent CABG before 1992 were analyzed. Thirty patients had a saphenous vein graft (SVG) only group, and the remaining 41 had a left internal thoracic artery graft to the left anterior descending coronary artery (LITA) group; 6 patients died from malignancy, which was the most common cause of death after CABG. The major adverse cardiac events (MACE) were defined as cardiac death, Q-wave or nonQ-wave myocardial infarction, and congestive heart failure. The MACE-free rate was significantly higher in the LITA group than in the SVG group (p < 0.05). However, among the patients with an ejection fraction < 0.40, there was no significant difference in MACE-free rate between the 2 groups. The LITA patency rate was significantly higher than that for SVG (p < 0.05) and the SVG patency rate was lower in the patients with hyperlipidemia (p < 0.05); cholesterol-lowering therapy improved the SVG patency rate. The long-term outcome of CABG was favorable, particularly if using an arterial graft. Although the patency rate was lower for the SVG than LITA, the patient's lipid profile might be an important factor in the SVG patency rate.

The SV stent study: a prospective, multicentre, angiographic evaluation of the BiodivYsio phosphorylcholine coated small vessel stent in small coronary vessels

Objective To evaluate the use of the phosphorylcholine (PC) coated BiodivYsio small vessel (SV) stent in native coronary vessels of small calibre. Design and setting Prospective, multi-centre, multi-national registry with 6-month clinical and core-lab angiographic follow-up. Adverse events were adjudicated by a Clinical Events Committee (CEC) and included peri-procedural analysis of cardiac enzymes. Patients Patients with signs or symptoms of ischaemia with an identified target lesion in an epicardial vessel with reference diameter 2.0–2.75 mm were enrolled. Intervention in other epicardial territories in the same patient was permitted. Results Recruitment of 150 consecutive lesions (in 143 patients) was completed in 19 centres in Europe and Israel. The stent was deployed successfully in all but one lesion. At 6 months, 1 patient (1%) had experienced sudden cardiac death, 4 further patients (3%) had a non-Q wave MI, and a further 24 patients (17%) had repeat revascularisation of a study target vessel. The mean reference vessel diameter prior to stenting was 2.2 mm (S.D. 0.4). Mean minimal luminal diameters at pre-procedure, post procedure and follow-up were 0.6 mm (S.D. 0.3), 2.0 mm (S.D. 0.4) and 1.2 mm (S.D. 0.6), respectively. The late lumen loss index was 0.55 (S.D. 0.53) with a binary restenosis rate of 32%. Conclusions In stenting of selected lesions in small vessels, the BiodivYsio SV™ stent demonstrated high rates of implant success. The rates of major adverse cardiac events (MACE), angiographic restenosis and repeat revascularisation are similar to those reported in other small vessel bare metal stent studies.

Rapamycin-eluting stents for the treatment of bifurcated coronary lesions: A randomized comparison of a simple versus complex strategy

Background Rapamycin-eluting stents (RES) have been shown to reduce restenosis in many types of lesions. However, the ideal strategy for the treatment of coronary bifurcated lesions has not been established to date. This randomized study compares 2 strategies for the RES treatment of bifurcation lesions: a simple approach (stenting the main vessel and balloon dilatation for the side branch [SB]) versus a complex approach (stents for both vessels). Methods To compare both strategies, a randomized study was conducted in 91 patients with true coronary bifurcation lestions. All patients received an RES at the main vessel, covering the SB. Patients from group A (n = 47) were assigned to balloon dilation of the involved SB (simple strategy); patients in group B (n = 44) were randomized to receive a second stent at the SB origin (complex strategy). There were no differences between groups regarding baseline clinical and angiographic data. Results Major adverse cardiac events occurred in 3 patients from group A (2 non-Q–wave myocardial infarctions and 1 target lesion revascularization). Six-month angiographic reevaluation was obtained in 80 patients (88%). Restenosis of the main vessel was observed in 1 (2%) patient from group A and in 4 (10%) from group B. Restenosis of the SB appeared in 2 (5%) patients from group A and in 6 (15%) from group B. Conclusions Both strategies are effective in reducing the restenosis rate, with no differences in terms of clinical outcome. Elective SB stenting seems to provide no advantages over the simpler stent jail followed by SB balloon dilation.

Rapamycin-eluting stents for the treatment of unprotected left main coronary disease

Background Conventional bare stents have been used to treat unprotected left main (LM) coronary artery stenosis. However, restenosis remains the main limitation. Since rapamycin-eluting stents (RES) appear to inhibit neointimal proliferation, their application to this specific site seems promising. Methods Since May 2002, we have studied a series of 52 patients with LM lesions treated with RES. Forty-seven patients presented with de novo stenoses, and 5 had in-stent restenosis; 19 patients required combined stent treatment for other remote lesions in the coronary tree, 6 of them at the level of proximal right coronary artery. The RES was implanted directly at the LM in 39 patients; 13 others needed predilation. Once deployed, the RES was overexpanded with short balloons adjusted to the LM length in 44 patients. Quantitative coronary angiograms were analyzed in the same view before and immediately after treatment and at follow-up. Patients were followed-up closely and new cardiac catheterization was scheduled at 6-month evaluation or earlier in the presence of symptoms. At follow-up study, quantitative coronary angiography and motorized intravascular ultrasound analyses were performed in 35 (67%) patients. Results Primary success was obtained in 50 patients (96%). Two patients (4%) developed a non-Q–wave myocardial infarction. All patients were symptom-free at discharge. After a mean follow-up of 12 ± 4 months, 50 patients (96%) remain asymptomatic. No late death or acute thrombosis have been recorded. Two patients became symptomatic 2 and 4 months after treatment, respectively. One had restenosis at a remote site, while the other had in-segment restenosis. None of the remaining 33 angiographically evaluated patients developed restenosis at any site. Target lesion revascularization was 1/52 (2%). Conclusions Although longer-term follow-up studies are needed, the tailored treatment of coronary lesions located at the LM by overexpanded RES is feasible and safe. Midterm results seem promising, which might help to shift the orientation of patient management from surgical to percutaneous revascularization.

Phase II trial of tamoxifen and interferon alpha in patients with metastatic or recurrent soft tissue sarcoma

9031 Background: Management of patients with advanced soft tissue sarcoma (STS) is difficult and often disappointing. We evaluated the role of Tamoxifen (T) and Interferon alpha 2b (I) for their anti-angiogenic properties in metastatic or recurrent STS. Methods: Patients with advanced STS who had failed at least one prior systemic therapy, with performance status of 0–2 on ECOG scale, and adequate organ functions were enrolled on this study between October 1999 and June 2003.Patients received 20 mg of Tamoxifen daily and subcutaneous Interferon alpha 2b (Schering-Plough) 3 million-unit/square meters three times weekly .Patients were evaluated for response at 8 weeks and at 6 months, and those with stable or responsive disease continued treatment up to 26 weeks after which treatment was discontinued and patients were followed. Results: Seventeen patients were enrolled on the study. All patients had received at east one prior chemotherapy regimen and 8 patients had received prior radiotherapy. Median age 56 years (27–76), Male/Female 11/6, 12 Caucasians. Median follow-up was 24 weeks (2–126 weeks). Two of the seventeen patients were not started on treatment due to rapidly deteriorating condition, 4 patients developed early severe toxicity and eventually were taken off protocol. Out of the 11 evaluable study patients, There was 1(7%) Complete remission with 70 weeks duration of response, no partial responses, and 2(13%) stable disease of 84 and 45 weeks duration, 8(53%) had progressive disease. Encountered Grade 3 and 4 toxicities included thrombocytopenia (1), neutropenia (1), abnormal LFTs (1) and non-Q wave myocardial infarction. No treatment related deaths were encountered. Conclusions: The combination of interferon and tamoxifen has activity in advanced STS, which warrants further evaluation. No significant financial relationships to disclose.

Phase II trial of tamoxifen and interferon alpha in patients with metastatic or recurrent soft tissue sarcoma

9031 Background: Management of patients with advanced soft tissue sarcoma (STS) is difficult and often disappointing. We evaluated the role of Tamoxifen (T) and Interferon alpha 2b (I) for their anti-angiogenic properties in metastatic or recurrent STS. Methods: Patients with advanced STS who had failed at least one prior systemic therapy, with performance status of 0–2 on ECOG scale, and adequate organ functions were enrolled on this study between October 1999 and June 2003.Patients received 20 mg of Tamoxifen daily and subcutaneous Interferon alpha 2b (Schering-Plough) 3 million-unit/square meters three times weekly .Patients were evaluated for response at 8 weeks and at 6 months, and those with stable or responsive disease continued treatment up to 26 weeks after which treatment was discontinued and patients were followed. Results: Seventeen patients were enrolled on the study. All patients had received at east one prior chemotherapy regimen and 8 patients had received prior radiotherapy. Median age 56 years (27–76), Male/Female 11/6, 12 Caucasians. Median follow-up was 24 weeks (2–126 weeks). Two of the seventeen patients were not started on treatment due to rapidly deteriorating condition, 4 patients developed early severe toxicity and eventually were taken off protocol. Out of the 11 evaluable study patients, There was 1(7%) Complete remission with 70 weeks duration of response, no partial responses, and 2(13%) stable disease of 84 and 45 weeks duration, 8(53%) had progressive disease. Encountered Grade 3 and 4 toxicities included thrombocytopenia (1), neutropenia (1), abnormal LFTs (1) and non-Q wave myocardial infarction. No treatment related deaths were encountered. Conclusions: The combination of interferon and tamoxifen has activity in advanced STS, which warrants further evaluation. No significant financial relationships to disclose.

Unstable angina

Properly treated unstable angina and non-Q wave myocardial infarction have low hospital mortality, but untreated, mortality is high. Symptoms and labs usually suffice for diagnosis. Abnormal physical findings are rarely helpful and often absent. Careful surveillance and management substantially reduce long-term risks.

Ischemic and viable myocardium in patients with Non–Q-Wave or Q-Wave myocardial infarction and left ventricular dysfunction: A clinical study using positron emission tomography, echocardiography, and electrocardiography

ObjectivesWe investigated whether patients with non–Q-wave myocardial infarction (NQMI) have more ischemic viable myocardium (IVM) than patients with Q-wave myocardial infarction (QMI). BackgroundNon–Q-wave myocardial infarction is associated with higher incidences of cardiac events than QMI, suggesting more myocardium at risk in NQMI. MethodsTo identify myocardial ischemia, hibernation, and scar, the resting and stress 82rubidium perfusion and F-18 fluorodeoxyglucose metabolic positron emission tomographic imaging (PET) was performed in 64 consecutive patients with NQMI (n = 21) or QMI (n = 43). Echocardiography was performed for assessment of left ventricular function and wall motion index (WMI). The relationships between PET, echocardiographic, and electrocardiographic findings were analyzed. ResultsThere were no significant differences in left ventricular ejection fraction (LVEF) between NQMI and QMI groups (28 ± 10% vs. 25 ± 11%, p > 0.05). Ischemic and viable myocardium was more common in NQMI than in QMI (91% vs. 61%, p < 0.05). The total amount of IVM was significantly higher in NQMI than in QMI (6.5 ± 5.2 vs. 2.9 ± 2.8 segments, p < 0.001). Neither the number of Q waves, residual ST-segment depression of ≥0.5 mm or elevation of ≥1 mm, nor LVEF and WMI were significant predictors for IVM. Wall motion index correlated with scar segments (r = 0.54, p < 0.001) and LVEF (r = −0.67, p < 0.001). ConclusionsIschemic and viable myocardium is common in patients with NQMI and left ventricular dysfunction, suggesting that aggressive approaches should be taken to salvage the myocardium at risk in such patients.

Usefulness of elevated neopterin and C-reactive protein levels in predicting cardiovascular events in patients with non–Q-wave myocardial infarction

The value of monocyte/macrophage activity as a prognostic factor in patients with non–Q-wave myocardial infarction (NQMI) has not yet been investigated. Moreover, scarce data are available on the long-term predictive value of markers of inflammation in patients who experience a NQMI. The present study aimed to determine the predictive value of neopterin, alone and in relation to levels of C-reactive protein, on the recurrence of major clinical cardiovascular events in patients who had a NQMI.

Does 24-hour ST-segment resolution postfibrinolysis add prognostic value to a Q wave? An ASSENT 2 electrocardiographic substudy

Background Both ST resolution and Q-wave development postfibrinolysis provide important prognostic insights in patients with acute myocardial infarction (MI). However, the relative contributions of these 2 factors to risk assessment have not been examined prospectively. Methods and results ST resolution and Q development were evaluated 24 to 36 hours (24–36h) postfibrinolysis in ASSENT-2: 13,100 out of 16,949 patients who had both baseline and 24–36h electrocardiograms free of confounders (left bundle branch block, ventricular rhythm, reinfarction before 24–36h electrocardiograms) were included in this analysis. Q-wave MI evolved in 10,466 patients (79.9%) and 2634 patients (20.1%) had non-Q–wave MI at 24–36h postfibrinolysis. Mortality rates at 1-year were 7.0% for patients with Q-wave MI and 5.8% for non-Q–wave MI patients, respectively ( P = .046). Patients with Q-wave MI versus those without were less likely to have complete ST-segment resolution (49.1% vs 59.1%) and more likely to have partial (37.1% vs 27.8%) or no resolution (13.8% vs 13.1%) at 24 to 36 hours postfibrinolysis ( P < .001). Mortality rates at 1 year for Q-wave MI with complete, partial, and no resolution were 5.2%, 8.1%, and 10.1%, respectively ( P < .001), and for non-Q–wave MI with complete, partial, and no resolution were 4.5%, 7.6%, and 8.0% ( P = .003). Conclusion These results demonstrate the additional prognostic significance of ST-segment resolution to Q-wave development at 24 to 36 hours after fibrinolysis.

Effect of direct stenting on clinical outcome in patients treated with percutaneous coronary intervention on saphenous vein graft

Background Percutaneous coronary intervention (PCI) of saphenous vein graft (SVG) is associated with frequent postprocedural enzyme elevation and late cardiac events. New strategies are proposed to minimize distal embolization and to improve the outcome of patients treated with stenting for SVG lesions. The objectives of the current study were to examine direct stenting (DS) strategy of PCI in SVG lesions and its effects on creatine-kinase (CK) release, major adverse cardiac events (MACE), and late outcome when compared to conventional stenting (CS). Methods A consecutive series of 527 patients treated with stent implantation for SVG stenosis was analyzed. In this cohort, 170 patients with 229 lesions were treated with DS and 357 patients with 443 lesions were treated with CS. The inhospital and 12-month follow-up events were recorded and reported. Results Baseline clinical and postprocedural angiographic characteristics were similar between the 2 groups except for higher preprocedural prevalence of thrombus-containing lesions in the DS group. Patients in the DS group had less CK-MB release ( P < .001), and less non-Q–wave myocardial infarction ( P = .024). Multivariate analysis detected unstable angina (odds ratio [OR] = 1.8, P = .03) as a correlate for non-Q–wave MI; DS was inversely associated with non-Q–wave myocardial infarction (OR = 0.65, P = .04). At 1 year, the target lesion revascularization-MACE was significantly lower in the DS group ( P = .021). Multivariate analysis showed that DS (OR = 0.47, P = .007) was associated with reduction of the target lesion revascularization-MACE. Conclusions When feasible, DS may be the best approach for treating SVG stenosis.

Angiographic and clinical characteristics associated with the development of q-wave and non-q–wave myocardial infarction in the thrombolysis in myocardial infarction (timi) 14 trial

Background In the absence of thrombolytic therapy, patients with non-Q–wave myocardial infarction (MI) have previously been shown to have lower long-term mortality rates than patients with Q-wave MI. The goal of our study was to examine the angiographic and clinical differences between non-Q–wave MI and Q-wave MI in patients with ST elevation MI (STEMI) in the era of thrombolytic and combination therapy of thrombolytics plus glycoprotein IIb/IIIa inhibitors. Methods Angiography was performed 90 minutes after thrombolytic administration in the Thrombolysis in Myocardial Infarction (TIMI) 14 trial. The development of a non-Q–wave MI was assessed on electrocardiogram performed at the time of hospital discharge. Angiographic findings were assessed at an angiographic core laboratory by blinded investigators. Results The qualifying episode of ST elevation developed into a non-Q–wave MI in 36% of patients (315/878) and into a Q-wave MI in 64% of patients (563/878). In patients in whom non-Q–wave MI developed, the rate of TIMI grade 3 flow was higher, peak creatine kinase level was lower, mean left ventricular ejection fraction was greater, corrected TIMI frame counts (CTFCs) were lower (ie, faster blood flow), and chest pain duration after thrombolytic administration was shorter. Patients in whom non-Q–wave MI developed less frequently underwent a percutaneous coronary intervention (PCI), and when they did, they had faster post-PCI CTFCs and higher rates of post-PCI TIMI grade 3 flow. Patients in whom a non-Q–wave MI developed had lower rates of severe recurrent ischemia. There were no differences in 30-day or in-hospital mortality rates or recurrent MI between patients with Q-wave MI and patients with non-Q–wave MI. Conclusion After thrombolytic therapy in STEMI with or without abciximab, ejection fractions were higher, the duration of ischemia was shorter, and coronary blood flow at both 90 minutes and after PCI was faster in patients who sustained non-Q–wave MI than in patients who sustained Q-wave MI. No differences in mortality or recurrent MI rates were detected in patients who sustained a Q-wave MI and patients in whom a Q-wave MI did not evolve in the modern thrombolytic era.

Cardiac risk stratification in patients undergoing endoluminal graft repair of abdominal aortic aneurysm: a single-institution experience with 365 patients.

Patients undergoing abdominal aortic aneurysm repair have a high incidence of coexisting cardiac disease. The traditional cardiac risk stratification for open abdominal aortic aneurysm surgery may not apply to patients undergoing endoluminal graft exclusion. The purpose of this study was to examine predictive risk factors for perioperative cardiac events. As part of multiple prospective endograft trials approved by the US Food and Drug Administration, data for 365 patients who underwent endoluminal graft repair from 1996 to 2001 were collected. Variables included for analysis were age and sex; history of smoking; presence of hypertension, diabetes mellitus, or renal insufficiency; Eagle clinical cardiac risk factors; American Society of Anesthesiologists index; type of anesthesia administered; estimated blood loss; preoperative hemoglobin level; preoperative use of beta-blocker therapy; duration of surgery; need for iliac artery conduit; and concomitant other vascular procedures. Univariate and multivariate logistic regression analysis were used to determine which variables were predictive of an adverse perioperative cardiac event, eg, Q wave and non-Q wave myocardial infarction (MI), congestive heart failure (CHF), severe arrhythmia, and unstable angina. The study cohort included 322 men and 43 women (mean age, 74.2 years). Fifty-two (14.2%) postoperative cardiac events occurred: severe dysrhythmia in 15 patients (4.1%), MI in 14 patients (3.8%), non-Q wave MI in 8 patients (2.2%), CHF in 8 patients (2.2%), and unstable angina in 7 patients (1.9%). Univariate analysis demonstrated that age 70 years or older (P =.034), history of MI (P =.018), angina (P =.004), history of CHF (P <.001), two or more Eagle risk factors (P <.001), and lack of use of preoperative beta-blocker therapy (P =.005) were predictors of perioperative cardiac events. Multivariate analysis identified only age 70 years or older (P =.026), history of MI (P =.024) or CHF (P =.001), and lack of use of preoperative beta-blocker therapy (P =.007) as independent risk factors for an adverse cardiac event. Age 70 years or older, history of MI or CHF, and lack of use of preoperative beta-blocker therapy are independent risk factors for perioperative cardiac events in patients undergoing endoluminal graft repair.

Indications of coronary cineangiography in coronary heart disease

Recent advances in Medical Science and the thechnological improvements in the field of myocardial revascularisation, in surgical procedures and in percutaneous interventions, made attractive the initial option for invasive strategies in the management of coronary heart disease. For this reason, coronary arteriography is nowadays more often indicated. Some concepts in coronary heart disease have been reviewed, specially those related to acute coronary syndromes. Non-ST-segment elevation myocardial infarction (previously called non-Q wave myocardial infarction) and unstable angina are now considered "unstable acute coronary syndromes" and both have the same guidelines for management. The main indications for coronary arteriography as the first diagnostic tool are: 1) incapacitating angina, even in stable patients; 2) high-risk patients with unstable coronary syndromes (refractory angina, troponin elevation, new ST- segment deviations, cardiac failure and serious arrythmias); 3) patients with acute ST-elevation myocardial infarction that will be submitted to primary angioplasty or with hemodynamic instability or persistent ischemia. Low-risk patients (angina that promptly subsides after medication, no electrocardiographic or laboratorial changes or atypical chest pain) may be submitted to non-invasive testing for further risk stratification; if no ischemia is detected, coronary arteriography is not indicated and optimized medical treatment is perfectly admitted for a great number of patients. The indications of coronary arteriography for the diagnosis and prognosis of coronary heart disease are not well delimited in clinical practice, and this method is frequently used as the first tool in the investigation of chest pain, even when the characteristics of pain are not exactly those of angina. In this review, the authors discuss the main indications of coronary arteriography in the multiple clinical aspects of coronary heart disease and in the differential diagnosis of chest pain.

The effect of the Q wave infarct on left ventricular electromechanical function

Objective: To assess the nature of left ventricular (LV) electrical and mechanical dysfunction in Q compared to non-Q anterior myocardial infarction (MI). Subjects: We used ECG and echocardiography to study 54 unselected patients, age 57±15 years, 32 male, with old (>6 months after) anterior MI (39 Q and 15 non-Q), confirmed by enzyme rise and regional wall motion abnormality, and compared them with 21 normals of similar age. Methods: Analysis of resting LV minor and long axis function and 12-lead surface electrocardiogram. Results: Only 10% of normals did not have a normal septal Q wave compared with 46% of non-Q wave MI and 84% Q wave MI ( P<0.001). All patients with Q wave MI had a scarred anteroseptal wall but none of the non-Q wave MI. LV minor axis dimensions were increased only with Q wave MI: 6.0±0.9 vs. 4.9±0.5 cm at end-diastole and 4.5±1.1 vs. 3.3±0.5 cm at end-systole and fractional shortening was reduced 27±8 vs. 33±3% ( P<0.001 for all). Total left ventricular long axis amplitude of motion was reduced at the left, septal and posterior sites only in Q wave MI but was not different from controls in non-Q wave MI. The onset of long axis shortening was delayed by 20 ms at the left and septal sites in non-Q wave MI and by an additional 20 ms at the three sites in Q wave MI. Peak long axis shortening rate was reduced in the two patient groups, with the same distribution as post-ejection shortening (greater than 1 mm), which occurred in 21% of patients with non-Q wave MI and 76% of patients with Q wave MI ( P<0.001). In diastole, the onset of long axis lengthening was delayed by 20 ms at the left and septal sites in non-Q wave MI and at the three sites in Q wave MI ( P<0.001). Peak long axis lengthening rate was reduced with a similar distribution in the two patient groups. Conclusion: Patients with Q wave MI have an increased LV dimension and reduced FS, whereas patients with non-Q wave MI appear to have morphologically normal LV minor axis dimensions and fractional shortening apart from the anterior wall hypokinesis. In the latter, however, long axis function shows significant systolic and diastolic disturbances affecting the anteroseptal and lateral walls. The absence of conduction disturbances in non-Q wave MI suggests intrinsic myocardial dysfunction that may be reversible.

Pathophysiology of valvular aortic stenosis in the elderly.

Aortic stenosis in the elderly is related to calcification of either a bicuspid valve or a morphologically normal tricuspid valve. There is increasing evidence that factors relating to atherosclerosis are involved in valvular calcification and that it is an actively regulated process rather than a degenerative one. With severe aortic stenosis left ventricular hypertrophy occurs, decreasing wall stress and supporting the left ventricular ejection fraction. However, with pathologic hypertrophy there is a dropout of myocardial cells, subendocardial ischemia, and fibrosis. Eventually, symptoms of angina, non-Q wave myocardial infarction, exertional syncope, and heart failure occur. Once symptoms begin, the prognosis is poor, with sudden death occurring in about one third of patients who die. In the elderly, symptoms can be recognized very late in the course of the disease since they can be attributed to other problems and since the elderly patient may have reduced physical activity to a minimum. The more comorbidities that exist, the greater the risk of valve replacement. Symptomatic patients with severe aortic stenosis even over age 80 can be operated upon with a relatively low mortality and morbidity. In patients over age 80, prolongation of life for any meaningful length of time is not as important as relief of symptoms and improvement in the quality of life. Thus, it is unlikely that any truly asymptomatic patient over age 80, even with severe aortic stenosis, should be sent to surgery.

Revascularization of chronic coronary artery occlusions using laser debulking followed by stent implantation

Objective — Chronic total occlusions are considered unfavourable for percutaneous balloon angioplasty because of the low rate of success and the high rate of restenosis. Stent implantation after recanalization of chronic total occlusions has been shown to reduce restenosis and reocclusion rates compared with balloon angioplasty in recently published randomized trials. However, it is not well known whether laser debulking before stent implantation would improve the benefit of stenting in chronic total occlusions.Methods and results — We analysed procedural and long-term clinical and angiographic followup results of 48 patients who underwent laser angioplasty followed by stent implantation for chronic total occlusions. The procedure was completed successfully in 46 patients (95.8%) in whom the lesion was crossed with a guidewire.We implanted 51 stents in 46 chronic total occlusions following laser debulking. During in-hospital follow-up 1 patient (2.1%) had Q wave, and 4 patients (8.7%) had non-Q wave myocardial infarction. Nine patients (19.5%) had repeat angioplasty for restenosis and one (2.1%) underwent coronary bypass operation at 6 months follow-up. Death or Q wave myocardial infarction did not occur during 6-month follow-up.Thirty-nine patients (85%) had angiographic follow-up at 6 months, and stent restenosis was found in 17 (44%) patients.Conclusion — These high rates of restenosis and target vessel revascularization in our study suggest that laser debulking before stent implantation does not improve clinical and angiogragic outcomes in chronic total occlusions.

Clopidogrel in acute coronary syndromes (unstable angina and non-Q-wave myocardial infarction).

Given the importance of thrombosis in acute coronary syndromes, antithrombotic therapy has become standard treatment for these conditions. This article reviews the mechanism of action and the major evidence supporting the clinical use of clopidogrel, a potent antiplatelet agent of the thienopyridines class, focusing on its role in the setting of acute coronary syndromes without persistent ST segment elevation (unstable angina and non-Q wave myocardial infarction). Some unanswered questions relating to this medication are also highlighted. Finally, current updates on clinical guidelines for the use of clopidogrel in acute coronary syndromes are discussed.