Predrag Mitrovic

Comparison of exercise, dobutamine-atropine and dipyridamole-atropine stress echocardiography in detecting coronary artery disease

BackgroundDipyridamole and dobutamine stress echocardiography testing are most widely utilized, but their sensitivity remained suboptimal in comparison to routine exercise stress echocardiography. The aim of our study is to compare, head-to-head, exercise, dobutamine and dipyridamole stress echocardiography tests, performed with state-of-the-art protocols in a large scale prospective group of patients.MethodsDipyridamole-atropine (Dipatro: 0.84 mg/kg over 10 min i.v. dipyridamole with addition of up to 1 mg of atropine), dobutamine-atropine (Dobatro: up to 40 mcg/kg/min i.v. dobutamine with addition of up to 1 mg of atropine) and exercise (Ex, Bruce) were performed in 166 pts. Of them, 117 pts without resting wall motion abnormalities were enrolled in study (91 male; mean age 54 ± 10 years; previous non-transmural myocardial infarction in 32 pts, angina pectoris in 69 pts and atypical chest pain in 16 pts). Tests were performed in random sequence, in 3 different days, within 5 day period under identical therapy. All patients underwent coronary angiography.ResultsSignificant coronary artery disease (CAD; ≥50% diameter stenosis) was present in 69 pts (57 pts 1-vessel CAD, 12 multivessel CAD) and absent in 48 pts. Sensitivity (Sn) was 96%, 93% and 90%, whereas specificity (Sp) was 92%, 92% and 87% for Dobatro, Dipatro and Ex, respectively (p = ns). Concomitant beta blocker therapy did not influence peak rate-pressure product and Sn of Dobatro and Dipatro (p = ns).ConclusionWhen state-of-the-art protocols are used, dipyridamole and dobutamine stress echocardiography have comparable and high diagnostic accuracy, similar to maximal post-exercise treadmill stress echocardiography.

The Timing of Infarction Pain in Patients with Acute Myocardial Infarction after Previous Revascularization

Circadian variation of onset of acute myocardial infarction (AMI) has been noted in many studies, but there are no data about subgroups of patients with previous coronary artery bypass grafting (CABG). Because of abnormalities in the circadian rhythm of autonomic tone after surgery, it was very interesting to analyze the circadian patterns in the onset of symptoms of AMI in various subgroups of 1784 patients with previous CABG. As in the other studies, a peak occurred in the morning hours with 26.3% of the patients, but there was a second nearly equal, but higher, peak (26.4%) in the evening hours. The subgroups with specific clinical characteristics exhibited different patterns that determined these peaks in all populations. In patients older than 70 years of age, in both sexes, in smokers, diabetics, in patients with hypertension, in those undergoing beta-blocker therapy, and in patients without previous angina, two nearly equal peaks were observed, with higher evening peaks, except in those patients with hypertension and without angina. Only one peak in the evening hours was observed in a subgroup of patients with previous congestive heart failure (CHF) and non-STEMI. The subgroup of patients with previous angina and previous AMI exhibited no discernible peaks. The distribution of time of onset within the four intervals was not uniform, and the difference was statistically significant only for patients undergoing beta-blocker therapy at time of onset (p = 0.0013), nonsmokers (p = 0.0283), and patients with non-STEMI (p = 0.0412). It is well known that patients with AMI have a dominant morning peak of circadian variation of onset. However, analyzing a different subgroup of patients with AMI after previous CABG, it was found that some subgroups had two peaks of onset, but a higher evening peak (patients older than 70 years of age, smokers, diabetics, and a group of patients who were taking beta-blocker therapy). This subgroup of patients, together with the subgroups of patients with a dominant evening peak (patients with CHF and those with non-STEMI) and with patients with no peak (patients with previous angina and previous AMI), probably appear to modify characteristic circadian variation of infarction onset, expressing a higher evening peak, respectively to the previous CABG, with adverse consequences for central nervous system functioning.

In-Hospital and Long-Term Prognosis after Myocardial Infarction in Patients with Prior Coronary Artery Bypass Surgery; 19-Year Experience

To present a 19-year experience of the prognosis of patients with acute myocardial infarction (AMI) and prior coronary artery bypass surgery (CABS), 748 patients with AMI after prior CABS (postbypass group) and a control group of 1080 patients with AMI, but without prior CABS, were analyzed. All indexes of infarct size were lower in the postbypass group. There was more ventricular fibrillation in the postbypass group. In-hospital mortality was similar (p = 0.3675). In the follow-up period, postbypass patients had more heart failure, recurrent CABS, reinfarction, and unstable angina than did control patients. Cumulative survival was better in the control group than in the postbypass group (p = 0.0403). Multiple logistic regression model showed that previous angina (p = 0.0005), diabetes (p = 0.0058), and age (p = 0.0102) were independent predictor factors for survival. Use of digitalis and diuretics, together with previous angina, also influenced survival (p = 0.0092), as well as male gender, older patients, and diabetes together (p = 0.0420). Patients with AMI after prior CABS had smaller infarct, but more reinfarction, reoperation, heart failure, and angina. Previous angina, diabetes, and age, independently, as well as use of digitalis and diuretics together with angina, and male gender, older patients, and diabetes together, influenced a worse survival rate in these patients.

Oxidative stress markers predict early left ventricular systolic dysfunction after acute myocardial infarction treated with primary percutaneous coronary intervention

BACKGROUND Despite successful primary percutaneous coronary intervention (PCI) after ST-segment elevation myocardial infarction (STEMI), some patients develop left ventricular systolic dysfunction (LVSD) and acute heart failure (HF). Identifying patients with an increased risk of developing LVSD by means of biomarkers may help select patients requiring more aggressive therapy. OBJECTIVES The aim of this study was to evaluate the relationship between the levels of oxidative stress markers and development of LVSD and acute HF early after STEMI. MATERIAL AND METHODS The study enrolled 148 patients with the first STEMI, who were treated by primary PCI < 12 h from the onset of symptoms. We assessed the impact of different biomarkers for developing LVSD and acute HF (Killip ≥ 2) including: markers of necrosis - peak creatine kinase (CK), markers of myocardial stretch - B-type natriuretic peptide (BNP), inflammatory markers - C-reactive protein (CRP), leucocyte and neutrophil count, as well as oxidative stress markers - total thiol groups, catalase, superoxide dismutase (SOD) and glutathione reductase (GR). RESULTS In multivariate analysis, thiol groups, peak CK, anterior wall infarction, and age were predictors of LVEF ≤ 40%. Out of 16 variables significantly associated with the Killip ≥ 2 in univariate logistic regression analysis, 5 appeared to be independently associated with acute HF in multivariate analysis: catalase, BNP, leucocytes, neutrophil count, and size of left atrium. CONCLUSIONS In this study, we have shown for the first time that thiol groups and catalase are independent predictors of STEMI complication - LVSD and acute HF, respectively. Beside routine used biomarkers of necrosis and myocardial stretch, thiol groups and catalase may provide additional information regarding the risk stratification.

Usefulness of NT-proBNP in the Follow-Up of Patients after Myocardial Infarction

Summary Background: Since serial analyses of NT-proBNP in patients with acute coronary syndromes have shown that levels measured during a chronic, later phase are a better predictor of prognosis and indicator of left ventricular function than the levels measured during an acute phase, we sought to assess the association of NT-proBNP, measured 6 months after acute myocardial infarction (AMI), with traditional risk factors, characteristics of in-hospital and early postinfarction course, as well as its prognostic value and optimal cut-points in the ensuing 1-year follow-up. Methods: Fasting venous blood samples were drawn from 100 ambulatory patients and NT-proBNP concentrations in lithium-heparin plasma were determined using a one-step enzyme immunoassay based on the »sandwich« principle on a Dimension RxL clinical chemistry system (DADE Behring-Siemens). Patients were followed-up for the next 1 year, for the occurrence of new cardiac events. Results: Median (IQR) level of NT-proBNP was 521 (335–1095) pg/mL. Highest values were mostly associated with cardiac events during the first 6 months after AMI. Negative association with reperfusion therapy for index infarction confirmed its long-term beneficial effect. In the next one-year follow-up of stable patients, multivariate Cox regression analysis revealed the independent prognostic value of NT-proBNP for new-onset heart failure prediction (p=0.014), as well as for new coronary events prediction (p=0.035). Calculation of the AUCs revealed the optimal NT-proBNP cut-points of 800 pg/mL and 516 pg/mL, respectively. Conclusions: NT-proBNP values 6 months after AMI are mainly associated with the characteristics of early infarction and postinfarction course and can predict new cardiac events in the next one-year follow-up.

B-type natriuretic peptide in outpatients after myocardial infarction: Optimized cut-off value for incident heart failure prediction

Higher levels of natriuretic peptides were identified in outpatients after myocardial infarction (MI) compared to the healthy population, even in the absence of heart failure (HF). Therefore, we assessed the optimal cut-off value of B-type natriuretic peptide (BNP) in relation to new-onset HF prediction in 79 post-MI patients with preserved left ventricular systolic function (ejection fraction >40%). Plasma BNP was measured by enzyme immunoassay, 6 months after MI and patients were followed-up for the next one year. Cox proportional regression model analysis revealed the independent prognostic value of BNP for HF prediction (p=0.005). As assessed by ROC analysis the optimal cut-off value of BNP was 175 pg/mL (sensitivity 82%; specificity 77%, AUC 0.77), associated with significantly different rates of incident HF by Kaplan-Meier analysis (p=0.001). In this population of outpatients with preserved left ventricular systolic function after MI, BNP strongly correlated with new-onset HF development at the optimal cut-off value of 175 pg/mL.

Delivery after assisted reproduction

The aim of the paper was to describe and compare means of deliveries after assisted conception and after spontaneous conception. The rapid spread of assisted reproductive technology (ART) is part of development of modern society. Study is retrospective, descriptive and analytical. Data were collected out of medical charts of patients of Hospital for gynecology and obstetrics CHC Zvezdara, who have delivered babies in this institution after using methods of ART during the years 2001 till 2011. There were 190 ART patients, age ranging from 21 to 56 years, on average 35.6 (± 4.7) years. Majority (94.6%) of women were primiparous, without previous miscarriages. The most frequently used method of ART is IVF/ET (94.8%, of which ICSI was performed in 6.53%). 42.1% of pregnancies were achieved after second attempt of IVF/ET. Pregnancies delivered vaginally lasted on average 38,7±1,2 week of gestation. Majority of premature infants (overall incidence of preamaturety was 20,2%) were born by urgent cesarean section. There were 5 extremely premature infants (2,17%). There was 17,4% of twin pregnancies, and almost all of them (92,5%) we delivered by cesarean section. Average birth weight was 3160g (± 600), and average body length on birth was 51cm (± 3). The most vital infants were born spontaneously (wirh mean Apgar score in the 5th minute of 9,08). During our first ART pregnancy experiences we performed no vaginal deliveries. Further on, evident decreasing trend of cesarean section made place for vaginal deliveries. This ratio in study population slowely approaches to the general population ratio, and for now it is 40:60 (vaginal:cesarean delivery). Current experiences encourage us to deal with ART pregnanices, as if they were spontaniously achieved, and to deliver them respecting obsteric indications.

The influence of antibiotics and statins on inflammation in coronary disease.

Cardiovascular system diseases are the leading cause of death in developed countries. According to the World Health Organization data, coronary artery disease is responsible for death of over seven million people per year, while only in the United States about two million patients are hospitalized with the diagnosis of acute coronary syndrome (acute myocardial infarction or unstable angina). The main cause of these diseases is arteriosclerosis. The arteriosclerotic process in the big arterial blood vessels begins very early, already in childhood. Risk factors for arteriosclerosis are: hypercholesterolemia, hypertension, diabetes mellitus, obesity, smoking and physical inactivity. The main mechanism is a modest, chronic inflammative reaction as a response to the blood vessel damage.