Roberto Bassan

Atrioventricular block in acute inferior wall myocardial infarction: Harbinger of associated obstruction of the left anterior descending coronary artery

In a prospective study 51 consecutive patients who survived the acute phase of inferior wall myocardial infarction underwent coronary arteriography. Eleven patients developed some degree of atrioventricular (AV) block in the acute phase of infarction that disappeared within a few days and was considered by electrocardiographic analysis to be located in the AV node. Patients with AV block during acute myocardial infarction had a significantly higher prevalence of left anterior descending coronary artery obstruction (91 versus 55%, p less than 0.05) than did patients without AV block and the obstruction preceded the exit of the first septal perforator branch in 73% of cases with heart block and in 30% of cases without block (p less than 0.01). The sensitivity, specificity and predictive values were 31, 95 and 91%, respectively, for the existence of left anterior descending coronary artery obstruction when AV block occurred during acute inferior myocardial infarction, and 40, 90 and 73%, respectively, for the occurrence of the coronary artery obstruction before the exit of the first septal perforator branch. Patients with inferior myocardial infarction and left anterior descending coronary artery obstruction have a sixfold greater chance of developing heart block in the acute phase of infarction than do patients with inferior infarction without such obstruction (p less than 0.05). These findings also support the observations that the proximal AV conduction system usually has a dual arterial blood supply from both the right and left anterior descending coronary arteries, and may explain the transient behavior of heart block and lack of necrosis of the AV node seen in these patients.

B-type natriuretic peptide: a strong predictor of early and late mortality in patients with acute chest pain without ST-segment elevation in the emergency department.

BackgroundThe prognostic importance of early measurement of B-type natriuretic peptide (BNP) in patients with acute chest pain while the diagnosis is still uncertain is unknown. We determined the prognostic value of BNP in these patients immediately after presenting to the emergency department. MethodsSeven hundred and twenty-three consecutive individuals with suspicious ischemic acute chest pain and no ST-segment elevation were prospectively evaluated using a systematic diagnostic strategy and followed for 1 year. Acute coronary syndrome was diagnosed in 326 patients during their hospital stay. ResultsIn the follow-up, 15 (2.1%) patients of the whole cohort died of cardiac cause at 1 month and 51 (7.1%) at 1 year. Patients who died had significantly higher admission BNP levels than survivors and this correlation proved linear according to quartile levels. Patients with BNP greater than 101 pg/ml had 13 times higher rate of 1-month mortality (P<0.0001) and 5.3 times higher rate of 1-year mortality (P<0.0001) than patients with BNP of 101 pg/ml or less. Multiple logistic regression analysis disclosed BNP as a strong independent predictor of 1-month and 1-year mortality adding significant prognostic information over traditional risk markers. ConclusionAdmission BNP is an independent and powerful marker of early and late cardiac mortality in patients with acute chest pain without ST-segment elevation. These results suggest that BNP should be measured upon arrival at the emergency department for risk stratification in all these patients.

Chest pain in the emergency room. Importance of a systematic approach

OBJECTIVE To evaluate the efficiency of a systematic diagnostic approach in patients with chest pain in the emergency room in relation to the diagnosis of acute coronary syndrome (ACS) and the rate of hospitalization in high-cost units. METHODS One thousand and three consecutive patients with chest pain were screened according to a preestablished process of diagnostic investigation based on the pre-test probability of ACS determinate by chest pain type and ECG changes. RESULTS Of the 1003 patients, 224 were immediately discharged home because of no suspicion of ACS (route 5) and 119 were immediately transferred to the coronary care united because of ST elevation or left bundle-branch block (LBBB) (route 1) (74% of these had a final diagnosis of acute myocardial infarction [AMI]). Of the 660 patients that remained in the emergency room under observation, 77 (12%) had AMI without ST segment elevation and 202 (31%) had unstable angina (UA). In route 2 (high probability of ACS) 17% of patients had AMI and 43% had UA, whereas in route 3 (low probability) 2% had AMI and 7% had UA. The admission ECG has been confirmed as a poor sensitivity test for the diagnosis of AMI (49%), with a positive predictive value considered only satisfactory (79%). CONCLUSION A systematic diagnostic strategy, as used in this study, is essential in managing patients with chest pain in the emergency room in order to obtain high diagnostic accuracy, lower cost, and optimization of the use of coronary care unit beds.

Chest Pain Units. A Modern Way of Managing Patients with Chest Pain in the Emergency Department

It is estimated that 5 to 8 million individuals with chest pain or other symptoms suggestive of myocardial ischemia are seen each year in emergency departments (ED) in the United States 1,2, which corresponds to 5 to 10% of all visits 3,4. Most of these patients are hospitalized for evaluation of possible acute coronary syndrome (ACS). This generates an estimated cost of 3 - 6 thousand dollars per patient 5,6. From this evaluation process, about 1.2 million patients receive the diagnosis of acute myocardial infarction (AMI), and just about the same number have unstable angina. Therefore, about one half to two thirds of these patients with chest pain do not have a cardiac cause for their symptoms 2,3. Thus, the emergency physician is faced with the difficult challenge of identifying those with ACS - a life-threatening disease - to treat them properly, and to discharge the others to suitable outpatient investigation and management.

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.

Efficacy of a diagnostic strategy for patients with chest pain and no ST-segment elevation in the emergency room

PURPOSE To evaluate the efficacy of a systematic model of care for patients with chest pain and no ST segment elevation in the emergency room. METHODS From 1003 patients submitted to an algorithm diagnostic investigation by probability of acute ischemic syndrome. We analyzed 600 ones with no elevation of ST segment, then enrolled to diagnostic routes of median (route 2) and low probability (route 3) to ischemic syndrome. RESULTS In route 2 we found 17% acute myocardial infarction and 43% unstable angina, whereas in route 3 the rates were 2% and 7%, respectively. Patients with normal/non-specific ECG had 6% probability of AMI whereas in those with negative first CKMB it was 7%; the association of the 2 data only reduced it to 4%. In patients in route 2 the diagnosis of AMI could only be ruled out with serial CKMB measurement up to 9 hours, while in route 3 it could be done in up to 3 hours. Thus, sensitivity and negative predictive value of admission CKMB for AMI were 52% and 93%, respectively. About one-half of patients with unstable angina did not disclose objective ischemic changes on admission. CONCLUSION The use of a systematic model of care in patients with chest pain offers the opportunity of hindering inappropriate release of patients with ACI and reduces unnecessary admissions. However some patients even with normal ECG should not be released based on a negative first CKMB. Serial measurement of CKMB up to 9 hours is necessary in patients with medium probability of AMI.

Safety, feasibility, and results of exercise testing for stratifying patients with chest pain in the emergency room

OBJECTIVE To assess safety, feasibility, and the results of early exercise testing in patients with chest pain admitted to the emergency room of the chest pain unit, in whom acute myocardial infarction and high-risk unstable angina had been ruled out. METHODS A study including 1060 consecutive patients with chest pain admitted to the emergency room of the chest pain unit was carried out. Of them, 677 (64%) patients were eligible for exercise testing, but only 268 (40%) underwent the test. RESULTS The mean age of the patients studied was 51.7 12.1 years, and 188 (70%) were males. Twenty-eight (10%) patients had a previous history of coronary artery disease, 244 (91%) had a normal or unspecific electrocardiogram, and 150 (56%) underwent exercise testing within a 12-hour interval. The results of the exercise test in the latter group were as follows: 34 (13%) were positive, 191 (71%) were negative, and 43 (16%) were inconclusive. In the group of patients with a positive exercise test, 21 (62%) underwent coronary angiography, 11 underwent angioplasty, and 2 underwent myocardial revascularization. In a univariate analysis, type A/B chest pain (definitely/probably anginal) (p<0.0001), previous coronary artery disease (p<0.0001), and route 2 (patients at higher risk) correlated with a positive or inconclusive test (p<0.0001). CONCLUSION In patients with chest pain and in whom acute myocardial infarction and high-risk unstable angina had been ruled out, the exercise test proved to be feasible, safe, and well tolerated.

Cardiovascular changes and cardiac morbidity of menopause. Effects of hormone replacement therapy

The cessation of cyclic ovulation and consequent interruption of estrogen production by follicular cells in the ovaries is a natural phenomenon in women around 50 years of age, representing the menopause or climacterium. However, menopause can also result from surgical bilateral oophorectomy in a still fertile woman. Independently of its mechanism, menopause causes important metabolic and cardiovascular changes in women, as shown by several case-controlled and cohort studies. These changes do not seem to be due to differences in age or other factors, suggesting that the cause is the reduction in estrogen levels. During a woman’s fertile years, coronary artery disease is rare, with a male-to-female ratio of at least 3:1, for age-matched individuals. After menopause, this ratio progressively decreases reaching 1:1, at the age of 75 and above . A 50-year-old woman has a 50% chance of developing coronary artery disease, and a 30% chance of dying from it during the postmenopausal years . For breast cancer, these ratios are 10% and 3%, and for endometrial cancer 3% and 0.3%, respectively. Thus, coronary artery disease is the major cause of death in adult woman (as it is for man) in developed countries. Although breast cancer is responsible for 43,000 deaths annually, and lung cancer for 51,000 deaths annually of women in the United States, coronary artery disease causes 236,000 annual deaths, and 87,000 strokes . Even though there was a 20% reduction in mortality resulting from coronary artery disease in women from 1979 to 1989, the absolute number of women dying due to this pathology continues to increase. With the progressive increase in life expectancy, the number of women older than 50, and consequently in menopause, is much higher today than in previous decades. In the United States, the average life expectancy for women is around 80, showing not only a higher number of postmenopausal women but also that these women will live more than one third of their lives deprived of estrogen. Menopause and atherosclerotic disease

Very Long-Term Prognostic Role of Admission BNP in Non-ST Segment Elevation Acute Coronary Syndrome

Background BNP has been extensively evaluated to determine short- and intermediate-term prognosis in patients with acute coronary syndrome, but its role in long-term mortality is not known. Objective To determine the very long-term prognostic role of B-type natriuretic peptide (BNP) for all-cause mortality in patients with non-ST segment elevation acute coronary syndrome (NSTEACS). Methods A cohort of 224 consecutive patients with NSTEACS, prospectively seen in the Emergency Department, had BNP measured on arrival to establish prognosis, and underwent a median 9.34-year follow-up for all-cause mortality. Results Unstable angina was diagnosed in 52.2%, and non-ST segment elevation myocardial infarction, in 47.8%. Median admission BNP was 81.9 pg/mL (IQ range = 22.2; 225) and mortality rate was correlated with increasing BNP quartiles: 14.3; 16.1; 48.2; and 73.2% (p < 0.0001). ROC curve disclosed 100 pg/mL as the best BNP cut-off value for mortality prediction (area under the curve = 0.789, 95% CI= 0.723-0.854), being a strong predictor of late mortality: BNP < 100 = 17.3% vs. BNP ≥ 100 = 65.0%, RR = 3.76 (95% CI = 2.49-5.63, p < 0.001). On logistic regression analysis, age >72 years (OR = 3.79, 95% CI = 1.62-8.86, p = 0.002), BNP ≥ 100 pg/mL (OR = 6.24, 95% CI = 2.95-13.23, p < 0.001) and estimated glomerular filtration rate (OR = 0.98, 95% CI = 0.97-0.99, p = 0.049) were independent late-mortality predictors. Conclusions BNP measured at hospital admission in patients with NSTEACS is a strong, independent predictor of very long-term all-cause mortality. This study allows raising the hypothesis that BNP should be measured in all patients with NSTEACS at the index event for long-term risk stratification.

Prognostic value of junctional recovery times and long-time follow-up of complete atrioventricular nodal block at a young age

Abstract The main purpose of clinical and electrophysiologic investigation in patients having complete atrioventricular (AV) nodal block is to differentiate between 2 different heterogeneous groups 1 : one presenting with syncope or other bradycardia/tachycardia-related symptoms 2 and the asymptomatic group. The data available at the present time do not allow us to conclude which criteria is the best to distinguish the patient at risk for syncope in the latter group. Even when the site of block is in the proximal part of the His bundle 1 with a good response to parasympathetic blockade 3 or to exercise, 4 the junctional rhythm may not be stable enough, and Adam-Stokes attacks may occur. 5 Some investigators believe that life-expectancy in symptomatic patients can be good. 6 However, others have recognized that life-threatening arrhythmias may develop, 7 and a prophylactic pacemaker should be implanted. 8