Essential thrombocythemia and acute myocardial infarction treated with rescue coronary angioplasty

A 48-year-old man with essential thrombocythemia suffered an extensive anterior acute myocardial infarction; this is a rare association. A pharmacological thrombolysis was performed, without success. He subsequently underwent successful rescue coronary angioplasty. To our knowledge, there is no other report in the literature relating the triad of essential thrombocythemia, acute myocardial infarction and rescue coronary angioplasty.

Primary coronary angioplasty and stent implantation in acute myocardial infarction. Comparative analysis of the in-hospital results in the CENIC/SBHCI registry

OBJECTIVE: Comparative analysis of the in-hospital results after primary implantation of stents or coronary balloon angioplasty in patients with acute myocardial infarction (MI). METHODS: CENIC (National Center of Cardiovascular Interventions) gathered data on 3,924 patients undergoing coronary angioplasty (in the primary form, without the previous use of thrombolytic agents) in the first 24 hours after a MI, during the period of 1996-1998. From these 3,924 patients, 1,337 (34%) underwent stent implantation. We analyzed the success of the procedure and the occurrence of adverse cardiac events. RESULTS: In patients undergoing stent implantation there were more males (77% vs 69%, p=0.001), previous by pass surgery (6.3% vs. 4.5%, p=0.01), anterior MI and stent implantation in left descending artery (55% vs. 48% vs. p=0.009), and saphenous vein bypass grafts (3.3% vs. 1.9%). the procedure was more succesful in the group of stents (97% vs. 84%, p=0.001) and reinfarction rate (2.5 vs. 4%, p=0.002). The need for emergency revascularization was similar (1% vs. 1.1%, NS). Total in-hospital mortality was lower in stent group (3.4% vs. 7. 2%, p=0.0001) and this effect was in patients Killip class III/V (19.5% vs. 32.5%, p= 0.002) because there was no difference in patients class I/II (1.7% vs. 2.8%, p=0.9). CONCLUSION: Primary stent implantation in acute myocardial infarction showed better early results than balloon angioplasty alome.

Bundle branch and atrioventricular block as complications of acute myocardial infarction in the thrombolytic era

OBJECTIVE: To analyze the incidence of intraventricular and atrioventricular conduction defects associated with acute myocardial infarction and the degree of in hospital mortality resulting from this condition during the era of thrombolytic therapy. METHODS: Observational study of a cohort of 929 consecutive patients with acute myocardial infarction. Multivariate analysis by logistic regression. Was used. RESULTS: Logistic regression showed a greater incidence of bundle branch block in male sex (odds ratio = 1.87, 95% CI = 1.02-3.42), age over 70 years (odds ratio = 2.31, 95% CI = 1.68-5.00), anterior localization of the infarction (odds ratio = 1.93, 95% CI = 1.03-3.65). There was a greater incidence of complete atrioventricular block in inferior infarcts (odds ratio = 2.59, 95% CI 1.30-5.18) and the presence of cardiogenic shock (odds ratio = 3.90, 95% CI = 1.43-10.65). Use of a thrombolytic agent was associated with a tendency toward a lower occurrence of bundle branch block (odds ratio = 0.68) and a greater occurrence of complete atrioventricular block (odds ratio = 1.44). The presence of bundle branch block (odds ratio = 2.45 95% , CI = 1.14-5.28) and of complete atrioventricular block (odds ratio = 13.59, 95% CI = 5.43-33.98) was associated with a high and independent probability of inhospital death. CONCLUSION: During the current era of thrombolytic therapy and in this population, intraventricular disturbances of electrical conduction and complete atrioventricular block were associated with a high and independent risk of inhospital death during acute myocardial infarction.

Is female sex an independent predictor of in-hospital mortality in acute myocardial infarction?

OBJECTIVE: To assess whether female sex is a factor independently related to in-hospital mortality in acute myocardial infarction. METHODS: Of 600 consecutive patients (435 males and 165 females) with acute myocardial infarction, we studied 13 demographic and clinical variables obtained at the time of hospital admission through uni- and multivariate analysis, and analyzed their relation to in-hospital death. RESULTS: Females were older (p<0.001) and had a higher incidence of hypertension (p<0.001). Males were more frequently smokers (p<0.001). The remaining risk factors had a similar incidence among both sexes. All variables underwent uni- and multivariate analysis. Through univariate analysis, the following variables were found to be associated with in-hospital death: female sex (p<0.001), age >70 years (p<0.001), the presence of previous coronary artery disease (p=0.0004), previous myocardial infarction (p<0.001), infarction in the anterior wall (p=0.007), presence of left ventricular dysfunction (p<0.001), and the absence of thrombolytic therapy (p=0.04). Through the multivariate analysis of logistic regression, the following variables were associated with in-hospital mortality: female sex (p=0.001), age (p=0.008), the presence of previous myocardial infarction (p=0.02), and left ventricular dysfunction (p<0.001). CONCLUSION: After adjusting for all risk variables, female sex proved to be a variable independently related to in-hospital mortality in acute myocardial infarction.

Analysis of the Prevalence of Ventricular Late Potentials in the Late Phase of Myocardial Infarction Based on the Site of Infarction

OBJECTIVE: The initial site of myocardial infarction (MI) may influence the prevalence of ventricular late potentials (VLP), high-frequency signals, due to the time course of ventricular activation. The prevalence of VLP in a period of more than 2 years after acute MI was assessed focusing on the initially injured wall . METHODS: The prevalence of VLP in a late phase after MI (median of 924 days) in anterior/antero-septal and inferior/infero-dorsal wall lesion was analyzed using signal-averaged electrocardiogram in time domain. The diagnostic performance of the filters employed for analysis on was tested at high-pass cut-off frequencies of 25 Hz, 40 Hz and 80 Hz. RESULTS: The duration of the ventricular activation and its terminal portion were larger in inferior than anterior infarction, at high-pass cut-off frequencies of 40 Hz and 80 Hz. In patients with ventricular tachycardia, these differences were more remarked. The prevalence of ventricular late potentials was three times greater in inferior than anterior infarction. CONCLUSION: Late after myocardial infarction, the prevalence and the duration of ventricular late potentials are greater in lesions of inferior/infero-dorsal than anterior/antero-septal wall confirming their temporal process, reflecting their high-frequency content.

Acute myocardial infarction in elderly patients: comparative analysis of the predictors of mortality. The elderly versus the young

OBJECTIVE: To study the in-hospital evolution of patients aged 65 years and older, with acute myocardial infarction, who were treated by direct coronary angioplasty with no fibrinolytic therapy. METHODS: We studied 885 patients divided into 2 groups as follows: group I (GI) - 293 (33.4%) patients aged ³ 65 years (72±5 years), and group II (GII) - 592 patients aged < 65 years (57±9 years). Multivessel disease was more frequent in GI (63.5% x 49.7%; p=0.001). A greater number of GII patients were class I or II of the clinical Killip-Kimball classification (K) (80.2% x 67.2%; p=0.00002), while a significant number of GI patients were KIII and KIV (24.3% x 12.8%; p=0.00003). RESULTS: Group I had a lower index of success (84.6% x 94%; p=0.0002) and a greater in-hospital mortality (12.2% x 4.7%; p=0.00007). The predictors of mortality in GI were as follows: previous infarction (20.5% x 6.3%; p=0.02), anterior location (13.4% x 6.4%; p=0.03), and male sex (10.4% x 4.4%; p=0.007). CONCLUSION: Elderly patients had more severe acute myocardial infarction and more extensive disease, a lower index of success, and greater in-hospital mortality. Previous infarction, anterior location and male sex were identified as predictors of mortality in the elderly group (GI).

Acute myocardial infarction: predictors of mortality at a public hospital in the city of Fortaleza, Ceará state

OBJECTIVE: To identify the clinical and demographic predictors of in-hospital mortality in acute myocardial infarction with elevation of the ST segment in a public hospital, in the city of Fortaleza, Ceará state, Brazil. METHODS: A retrospective study of 373 patients experiencing their first episode of acute myocardial infarction was carried out. Of the study patients, 289 were discharged from the hospital (group A) and 84 died (group B). Both groups were analyzed regarding: sex; age; time elapsed from the beginning of the symptoms of myocardial infarction to assistance at the hospital; use of streptokinase; risk factors for atherosclerosis; electrocardiographic location of myocardial infarct; and Killip functional class. RESULTS: In a univariate analysis, group B had a greater proportion of the following parameters as compared with group A: non-Killip I functional class; diabetes; age >70 years; infarction of the inferior wall associated with right ventricular impairment; time between symptom onset and treatment at the hospital >12 h; anteroseptal or extensive anterior infarction; no use of streptokinase; and no tobacco use. In a multivariate logistic regression analysis, only non-Killip I functional class, diabetes, and age >70 years persisted as independent factors for death. CONCLUSION: Non-Killip I functional class, diabetes, and age >70 years were independent predictors of mortality in acute myocardial infarction with elevation of the ST segment.

Infarct Size as Predictor of Systolic Functional Recovery after Myocardial Infarction

Background: The effects of modern therapy on functional recovery after acute myocardial infarction (AMI) are unknown.Objectives:To evaluate the predictors of systolic functional recovery after anterior wall AMI in patients undergoing modern therapy (reperfusion, aggressive platelet antiaggregant therapy, angiotensin-converting enzyme inhibitors and beta-blockers).Methods:A total of 94 consecutive patients with AMI with ST-segment elevation were enrolled. Echocardiograms were performed during the in-hospital phase and after 6 months. Systolic dysfunction was defined as ejection fraction value < 50%.Results:In the initial echocardiogram, 64% of patients had systolic dysfunction. Patients with ventricular dysfunction had greater infarct size, assessed by the measurement of total and isoenzyme MB creatine kinase enzymes, than patients without dysfunction. Additionally, 24.5% of patients that initially had systolic dysfunction showed recovery within 6 months after AMI. Patients who recovered ventricular function had smaller infarct sizes, but larger values of ejection fraction and E-wave deceleration time than patients without recovery. At the multivariate analysis, it can be observed that infarct size was the only independent predictor of functional recovery after 6 months of AMI when adjusted for age, gender, ejection fraction and E-wave deceleration time.Conclusion: In spite of aggressive treatment, systolic ventricular dysfunction remains a frequent event after the anterior wall myocardial infarction. Additionally, 25% of patients show functional recovery. Finally, infarct size was the only significant predictor of functional recovery after six months of acute myocardial infarction.

Neural Mechanisms and Delayed Gastric Emptying of Liquid Induced Through Acute Myocardial Infarction in Rats

Background: In pathological situations, such as acute myocardial infarction, disorders of motility of the proximal gut can trigger symptoms like nausea and vomiting. Acute myocardial infarction delays gastric emptying (GE) of liquid in rats. Objective: Investigate the involvement of the vagus nerve, α 1-adrenoceptors, central nervous system GABAB receptors and also participation of paraventricular nucleus (PVN) of the hypothalamus in GE and gastric compliance (GC) in infarcted rats. Methods: Wistar rats, N = 8-15 in each group, were divided as INF group and sham (SH) group and subdivided. The infarction was performed through ligation of the left anterior descending coronary artery. GC was estimated with pressure-volume curves. Vagotomy was performed by sectioning the dorsal and ventral branches. To verify the action of GABAB receptors, baclofen was injected via icv (intracerebroventricular). Intravenous prazosin was used to produce chemical sympathectomy. The lesion in the PVN of the hypothalamus was performed using a 1mA/10s electrical current and GE was determined by measuring the percentage of gastric retention (% GR) of a saline meal. Results: No significant differences were observed regarding GC between groups; vagotomy significantly reduced % GR in INF group; icv treatment with baclofen significantly reduced %GR. GABAB receptors were not conclusively involved in delaying GE; intravenous treatment with prazosin significantly reduced GR% in INF group. PVN lesion abolished the effect of myocardial infarction on GE. Conclusion: Gastric emptying of liquids induced through acute myocardial infarction in rats showed the involvement of the vagus nerve, alpha1- adrenergic receptors and PVN.

Rosuvastatin prevents myocardial necrosis in an experimental model of acute myocardial infarction

Dyslipidemia is related to the progression of atherosclerosis and is an important risk factor for acute coronary syndromes. Our objective was to determine the effect of rosuvastatin on myocardial necrosis in an experimental model of acute myocardial infarction (AMI). Male Wistar rats (8-10 weeks old, 250-350 g) were subjected to definitive occlusion of the left anterior descending coronary artery to cause AMI. Animals were divided into 6 groups of 8 to 11 rats per group: G1, normocholesterolemic diet; G2, normocholesterolemic diet and rosuvastatin (1 mg·kg-1·day-1) 30 days after AMI; G3, normocholesterolemic diet and rosuvastatin (1 mg·kg-1·day-1) 30 days before and after AMI; G4, hypercholesterolemic diet; G5, hypercholesterolemic diet and rosuvastatin (1 mg·kg-1·day-1) 30 days after AMI; G6, hypercholesterolemic diet and rosuvastatin (1 mg·kg-1·day-1) 30 days before and after AMI. Left ventricular function was determined by echocardiography and percent infarct area by histology. Fractional shortening of the left ventricle was normal at baseline and decreased significantly after AMI (P < 0.05 in all groups), being lower in G4 and G5 than in the other groups. No significant difference in fractional shortening was observed between G6 and the groups on the normocholesterolemic diet. Percent infarct area was significantly higher in G4 than in G3. No significant differences were observed in infarct area among the other groups. We conclude that a hypercholesterolemic diet resulted in reduced cardiac function after AMI, which was reversed with rosuvastatin when started 30 days before AMI. A normocholesterolemic diet associated with rosuvastatin before and after AMI prevented myocardial necrosis when compared with the hypercholesterolemic condition.

Air pollution effects on myocardial infarction

OBJECTIVE: Myocardial infarction is an acute and severe cardiovascular disease that generally leads to patient admissions to intensive care units and few cases are initially admitted to infirmaries. The objective of the study was to assess whether estimates of air pollution effects on myocardial infarction morbidity are modified by the source of health information. METHODS: The study was carried out in hospitals of the Brazilian Health System in the city of São Paulo, Southern Brazil. A time series study (1998-1999) was performed using two outcomes: infarction admissions to infirmaries and to intensive care units, both for people older than 64 years of age. Generalized linear models controlling for seasonality (long and short-term trends) and weather were used. The eight-day cumulative effects of air pollutants were assessed using third degree polynomial distributed lag models. RESULTS: Almost 70% of daily hospital admissions due to myocardial infarction were to infirmaries. Despite that, the effects of air pollutants on infarction were higher for intensive care units admissions. All pollutants were positively associated with the study outcomes but SO2 presented the strongest statistically significant association. An interquartile range increase on SO2 concentration was associated with increases of 13% (95% CI: 6-19) and 8% (95% CI: 2-13) of intensive care units and infirmary infarction admissions, respectively. CONCLUSIONS: It may be assumed there is a misclassification of myocardial infarction admissions to infirmaries leading to overestimation. Also, despite the absolute number of events, admissions to intensive care units data provides a more adequate estimate of the magnitude of air pollution effects on infarction admissions.

Acute myocardial infarction in chronic Chagas' cardiomyopathy: report of two cases with no obstructive coronary artery lesions

This report describes two patients with chronic Chagas' Heart Disease who developed clinical and laboratorial signs of myocardial infarction. Both patients presented sudden oppressive chest pain, without precipitating factor. In the first case, the highest MB-CK value was 65 IU, 22 hours after the beginning of the pain. On the second case, it was 77 IU at 18 hours after the beginning of the pain. In both cases ECG changes suggesting non-transmural infarction were present. The 99mTc PYP myocardial scintigram of the first case was positive. Coronary angiograms performed on the 18th and 9th day, respectively, after the acute infarction did not display obstructive lesions. Possible mechanisms causing myocardial infarction with normal coronary arteries in Chagas' Disease may include: embolic event's, particularly when there is associated congestive heart failure; coronary thrombosis and coronary spasms.

Infectious agents in coronary atheromas: a possible role in the pathogenesis of plaque rupture and acute myocardial infarction

In this review we report our recent findings of histopathological features of plaque instability and the association with Mycoplasma pneumoniae (MP) and Chlamydia pneumoniae (CP) infection, studying thrombosed coronary artery segments (CAS) of patients who died due to acute myocardial infarction. Vulnerable plaques are known to be associated with fat atheromas and inflammation of the plaque. Here we demonstrated that vulnerability is also related with focal positive vessel remodeling that maintains relatively well preserved lumen even in the presence of large atheromatous plaques. This phenomena may explain why the cinecoronariography may not detect large and dangerous vulnerable plaques. Greater amount of these bacteria in vulnerable plaques is associated with adventitial inflammation and positive vessel remodeling: the mean numbers of lymphocytes were significantly higher in adventitia than in the plaque, good direct correlation was obtained between numbers of CD20 B cells and numbers of CP infected cells in adventitia, and between % area of MP-DNA in the plaque and cross sectional area of the vessel, suggesting a cause-effect relationship. Mycoplasma is a bacterium that needs cholesterol for proliferation and may increase virulence of other infectious agents. In conclusion, co-infection by Mycoplasma pneumoniae and Chlamydia pneumoniae may represent an important co-factor for plaque instability, leading to coronary plaque thrombosis and acute myocardial infarction, since larger amount of these bacteria strongly correlated with histological signs of more vulnerability of the plaque. The search of CMV and Helicobacter pilori in these tissues resulted negative.

Detection of the viable myocardium. A perfusion scintigraphic study, before and after coronary bypass surgery in myocardial infarction patients

OBJECTIVE: To compare single-photon-emission computed tomography (SPECT) imaging scans using 201Tl and 99mTc-MIBI in detection of viable myocardium, in regions compromised by infarction. METHODS: Thirty-two (59.3±9.8 years old and 87% male) myocardial infarction patients were studied. All had Q waves on the ECG and left ventricle ejection fraction of <50%. They underwent coronary and left ventricle angiographies and SPECT before (including 201Tl reinjection) and after coronary artery bypass surgery (CABG). Improvement in perfusion observed after surgery was considered the gold standard for myocardial viability. RESULTS: Among 102 studied regions of the heart, there were 40 (39.2%) areas of transient perfusion defects in the conventional protocol with 201Tl and 52 (51.0%) after reinjection. Therefore, 12/62 (19.4%) more viable regions were identified by reinjection. Using 99mTc-MIBI, only 14 (13.7%) regions with transient defects were identified, all of which were seen also in 201Tl protocols. After surgery, 49 of a total of 93 regions analyzed (52.7%) were viable. Sensitivity, specificity, accuracy, positive and negative prediction values were, respectively, 201Tl SPECT scans - 65.3%, 90.9%, 77.4%, 88.9% and 70.2%, reinjection protocol with 201Tl scans - 81.6%, 81.8%, 81.7%, 83.3% and 80.0%; 99mTc-MIBI SPECT scans - 20.4%, 90.9%, 53.8%, 71.4% and 50.6%. Logistic regression demonstrated that the reinjection protocol with 201Tl was the best predictor of viability (P<0.001). CONCLUSION: Our data suggest the election of 201Tl for viability studies, especially when using the reinjection protocol.