Branko Beleslin

Stress echocardiography in the detection of myocardial ischemia. Head-to-head comparison of exercise, dobutamine, and dipyridamole tests.

BackgroundExercise and pharmacological stress echocar-diography have emerged as convenient alternatives to myocardial scintigraphy. The objective of this study was to compare in the same patients the diagnostic values of exercise, dobutamine, and dipyridamole stress echocardiography tests for detection of myocardial ischemia. Methods and ResultsWe performed exercise (maximal treadmill Bruce protocol), dobutamine (up to 40 μg/kg per minute) and dipyridamole (up to 0.84 mg/kg over 10 minutes) stress echocardiography tests, in random sequence and on separate days, in 136 consecutive patients. All patients underwent coronary angiography. Significant coronary artery disease was defined by quantitative coronary angiography as a lesion with a diameter stenosis ≥50%. A stress echocardiogram was considered positive when new or worsening of preexisting wall motion abnormality was observed. Most of the patients (94%) were receiving the same antianginal medication for each stress test; 59 patients were receiving concomitant β-blocker therapy. The prevalence of coronary artery disease was 87.5%, with 108 patients having one-vessel coronary artery disease. Peak heart rate and systolic blood pressure were higher with exercise than with dobutamine or dipyridamole (P<.01). Sensitivity of exercise, dobutamine, and dipyridamole stress echocardiography was 88%, 82%, and 74% (dipyridamole versus exercise, P<.01), respectively. Specificity was 82%, 77%, and 94%, respectively. The overall accuracy was 87%, 82%, and 77% (dipyridamole versus exercise, P<.01), respectively. The accuracy of dipyridamole was higher (P=.02) in the group of patients not receiving β-blockers (84%) than in the patients receiving β-blocker therapy (66%), whereas the accuracy of exercise and dobutamine were only slightly higher in the patients not receiving, β-blockers. Significant side effects occurred in 3%, 11%, and 1% of patients during exercise, dobutamine, and dipyridamole tests, respectively. ConclusionsDespite the different hemodynamic effects, exercise, dobutamine, and dipyridamole echocardiography have high overall diagnostic values. In this group of patients with a predominance of one-vessel coronary artery disease, the overall diagnostic accuracy of stress echocardiography tests was higher for exercise than for dobutamine or dipyridamole. Concomitant β-blocker therapy significantly decreased the accuracy of the dipyridamole stress echocardiography test. Pharmacological stress testing (dipyridamole without β-blockers) can therefore be used as an efficient option for detection of myocardial ischemia in patients who are unable or poorly motivated to exercise adequately.

Differential Effects of Drug-Eluting Stents on Local Endothelium-Dependent Coronary Vasomotion

OBJECTIVES The aim of our study was to compare coronary vasomotion after implantation of a second-generation biolimus A9-eluting stent (BES) and of a sirolimus-eluting stent (SES). BACKGROUND Drug-eluting stents (DES) have been associated with impaired local coronary vasomotion, delayed endothelialization, and increased late thrombotic risk. New DES with different drugs, pharmacokinetics, and polymers have been developed. METHODS Nineteen patients with a BES and 15 patients with a SES were studied 9 months after stent implantation. Endothelium-dependent and -independent coronary vasomotion were tested proximally and distally to the stent as well as at a reference segment during right atrial pacing at increasing heart rates. Quantitative coronary angiographic measurements were performed offline. RESULTS Of the patients with BES, 2 showed vasoconstriction with increased heart rate and 17 showed vasodilatation. Of the patients with a SES, 9 showed vasoconstriction while 6 showed vasodilatation. The SES showed significant vasoconstriction at both the proximal (-2.3 +/- 10% vs. 7.9 +/- 10%) and the distal (-5.4 +/- 9% vs. 6.1 +/- 8%) segments to the stent compared with the BES (p = 0.003 for proximal, p < 0.001 for distal segment). Endothelium-independent vasomotion after intracoronary nitrates did not differ significantly between the 2 groups (p = NS for proximal and distal segment). CONCLUSIONS Unlike the case with the SES, endothelium-dependent vasomotion at adjacent stent segments seems to be preserved after BES implantation. This result may be explained by the different drug release kinetics, DES design, or characteristics of polymer used in the stent system.

A 12-year follow-up study of patients with newly diagnosed lone atrial fibrillation: implications of arrhythmia progression on prognosis: the Belgrade Atrial Fibrillation study.

BACKGROUND Lone atrial fibrillation (AF) has been suggested to have a favorable long-term prognosis. Significant interest has been directed at factors predicting arrhythmia progression, and the HATCH score (hypertension, age ≥ 75 years, transient ischemic attack or stroke [2 points], COPD, and heart failure [2 points]) recently has been proposed as a predictive score for AF progression. We investigated long-term outcomes in a large cohort of newly diagnosed lone AF and whether progression from paroxysmal to permanent AF confers an adverse impact on outcomes, including stroke and thromboembolism. METHODS The study was an observational cohort of 346 patients with newly diagnosed lone AF with a mean follow-up of 12.1 ± 7.3 years. RESULTS Baseline paroxysmal AF was confirmed in 242 patients, and of these, 65 (26.9%) subsequently experienced progression to permanent AF. Older age and development of congestive heart failure during follow-up were the multivariate predictors of AF progression (both P < .01), which was documented in 19.8% of patients with a HATCH score of 0 vs 63.2% with a score of 2 (P < .001), although the predictive validity of the HATCH score per se was modest (C statistic, 0.6). The annual rate of thromboembolism and heart failure during follow-up were low (0.4% each), and five patients (1.4%) died. AF progression, development of cardiac diseases, and older age were multivariate predictors of adverse outcomes, including thromboembolism (all P < .05). Baseline CHADS(2) (congestive heart failure, hypertension, age ≥ 75, diabetes mellitus, prior stroke or transient ischemic attack) score was not predictive for thromboembolism (C statistic, 0.50; 95% CI, 0.31-0.69). CONCLUSIONS This 12-year follow-up study provides confirmatory evidence of a generally favorable prognosis of lone AF, but adverse outcomes (including stroke and thromboembolism) are significantly influenced by age and the (new) development of underlying heart disease. Arrhythmia progression in lone AF is a marker of increased risk for adverse cardiovascular events.

First clinical comparison of Nobori -Biolimus A9 eluting stents with Cypher- Sirolimus eluting stents: Nobori Core nine months angiographic and one year clinical outcomes.

AIM To compare clinical efficacy and safety of stents eluting limus drugs from biodegradable polymer - Nobori, or durable polymer - Cypher. METHODS AND RESULTS From May to August 2006, 107 patients with 142 coronary artery lesions were treated with either Nobori, Biolimus A9 eluting stent (54) or Cypher, Sirolimus eluting stent (53) in five centres. The two groups were well matched for baseline clinical and angiographic characteristics. The in-stent late loss at nine months, the primary endpoint of the study, was 0.10+/-0.26 mm in Nobori, and 0.13+/-0.44 mm in Cypher arm (p=0.660) confirming the hypothesis of the similarity between the two stents. In-stent diameter stenosis of 13+/-10% with Nobori was significantly lower than 20+/-12% with Cypher stent (p=0.002) without significant difference in binary restenosis (1.7% in Nobori and 6.3% in Cypher arm; p=0.32). The rate of major adverse cardiac events at 12 months was 1.9% with Nobori and 4.1% with Cypher stent. CONCLUSIONS The nine months angiographic data from Nobori Core study demonstrate that Biolimus A9 has similar anti-proliferative efficacy to Sirolimus as judged by in-stent late loss and restenosis rate. Low frequency of adverse cardiac events at 12 months indicates that both stents are safe and effective in the studied population.

Dipyridamole-dobutamine echocardiography: A novel test for the detection of milder forms of coronary artery disease

OBJECTIVES This study was designed to assess the clinical, hemodynamic and diagnostic effects of the addition of dobutamine to dipyridamole echocardiography. BACKGROUND Pharmacologic stress echocardiography with either dipyridamole or dobutamine has gained acceptance because of its safety, feasibility, diagnostic accuracy and prognostic power. The main limitation of the two tests is a less than ideal sensitivity in some patient subsets, such as those with limited coronary artery disease. We hypothesized that two pharmacologic stresses might act synergistically in the induction of ischemia by combining the mechanisms of inappropriate coronary vasodilation (with dipyridamole) and an increase in myocardial oxygen consumption (with dobutamine). METHODS One hundred fifty patients (mean [+/- SD] age 51 +/- 11 years) referred for stress echocardiography were initially studied by dipyridamole-dobutamine echocardiography. The test was stopped during the dipyridamole step in 95 patients for achievement of a predetermined end point (obvious dyssynergy induced by lower or higher dipyridamole dose), and dipyridamole-dobutamine tests were performed in 55 patients (negative dipyridamole echocardiographic test). In the same 150 patients the dobutamine echocardiographic test (up to 40 micrograms/kg body weight per min) was performed on a separate day. RESULTS Significant coronary artery disease (> 50% diameter stenosis of at least one major coronary vessel by quantitative coronary arteriography) was present in 131 patients (one vessel in 115; two vessels in 10, three vessels in 6), with normal coronary arteriography in 19. The feasibility of the dipyridamole-dobutamine test was 96%. Self-limiting side effects occurred in 5% of patients. The peak rate-pressure product was lowest during the dipyridamole test (132 +/- 30) and was comparable during the dobutamine (186 +/- 59) and dipyridamole-dobutamine tests (179 +/- 45, p = NS vs. dobutamine; p < 0.01 vs. dipyridamole). Sensitivity was 71% for dipyridamole, 75% for dobutamine and 92% for dipyridamole-dobutamine echocardiography (dipyridamole vs. dipyridamole-dobutamine, p < 0.01; dobutamine vs. dipyridamole-dobutamine, p < 0.01; dipyridamole vs. dobutamine, p = NS), whereas specificity was 89% for dipyridamole, 79% for dobutamine and 89% for dipyridamole-dobutamine echocardiography (p = NS for all). CONCLUSIONS Routine dobutamine addition to dipyridamole stress testing is clinically useful and well tolerated. It expands the spectrum of the disease detectable by pharmacologic stress echocardiography and allows documentation of milder forms of coronary artery disease that can be missed by conventional dipyridamole or dobutamine stress echocardiography.

Cardiopoietic cell therapy for advanced ischemic heart failure: results at 39 weeks of the prospective, randomized, double blind, sham-controlled CHART-1 clinical trial

Aims Cardiopoietic cells, produced through cardiogenic conditioning of patients’ mesenchymal stem cells, have shown preliminary efficacy. The Congestive Heart Failure Cardiopoietic Regenerative Therapy (CHART-1) trial aimed to validate cardiopoiesis-based biotherapy in a larger heart failure cohort. Methods and results This multinational, randomized, double-blind, sham-controlled study was conducted in 39 hospitals. Patients with symptomatic ischaemic heart failure on guideline-directed therapy (n = 484) were screened; n = 348 underwent bone marrow harvest and mesenchymal stem cell expansion. Those achieving > 24 million mesenchymal stem cells (n = 315) were randomized to cardiopoietic cells delivered endomyocardially with a retention-enhanced catheter (n = 157) or sham procedure (n = 158). Procedures were performed as randomized in 271 patients (n = 120 cardiopoietic cells, n = 151 sham). The primary efficacy endpoint was a Finkelstein–Schoenfeld hierarchical composite (all-cause mortality, worsening heart failure, Minnesota Living with Heart Failure Questionnaire score, 6-min walk distance, left ventricular end-systolic volume, and ejection fraction) at 39 weeks. The primary outcome was neutral (Mann–Whitney estimator 0.54, 95% confidence interval [CI] 0.47–0.61 [value > 0.5 favours cell treatment], P = 0.27). Exploratory analyses suggested a benefit of cell treatment on the primary composite in patients with baseline left ventricular end-diastolic volume 200–370 mL (60% of patients) (Mann–Whitney estimator 0.61, 95% CI 0.52–0.70, P = 0.015). No difference was observed in serious adverse events. One (0.9%) cardiopoietic cell patient and 9 (5.4%) sham patients experienced aborted or sudden cardiac death. Conclusion The primary endpoint was neutral, with safety demonstrated across the cohort. Further evaluation of cardiopoietic cell therapy in patients with elevated end-diastolic volume is warranted.

The Pharmacokinetics of Biolimus A9 after Elution from the Nobori Stent in Patients with Coronary Artery Disease: The NOBORI PK Study

The aim of this study was to assess the pharmacokinetics and tolerability of Biolimus A9 eluted from Nobori coronary stents.

Integrated evaluation of relation between coronary lesion features and stress echocardiography results: the importance of coronary lesion morphology

OBJECTIVES The aim of this study was to analyze, in the same group of patients, the relationship between multiple variables of coronary lesion and results of exercise, dobutamine and dipyridamole stress echocardiography tests. BACKGROUND Integrated evaluation of the relation between stress echocardiography results and angiographic variables should include not only the assessment of stenosis severity but also evaluation of other quantitative and qualitative features of coronary stenosis. METHODS Study population consisted of 168 (138 male, 30 female, mean age 51+/-9 years) patients, on whom exercise (Bruce treadmill protocol), dobutamine (up to 40 mcg/kg/min) and dipyridamole (0.84 mg/kg over 10 min) stress echocardiography tests were performed. Stress echocardiography test was considered positive for myocardial ischemia when a new wall motion abnormality was observed. One-vessel coronary stenosis ranging from mild stenosis to complete obstruction of the vessel was present in 153 patients, and 15 patients had normal coronary arteries. The observed angiographic variables included particular coronary vessel, stenosis location, the presence of collaterals, plaque morphology according to Ambrose classification, percent diameter stenosis and obstruction diameter as assessed by quantitative coronary arteriography. RESULTS Covariates significantly associated with the results of physical and pharmacological stress tests included for all three stress modalities presence of collateral circulation, percent diameter stenosis and obstruction diameter, as well as lesion morphology (p < 0.05 for all, except collaterals for dobutamine stress test, p = 0.06). By stepwise multiple logistic regression analysis, the strongest predictor of the outcome of exercise echocardiography test was only percent diameter stenosis (p = 0.0002). However, both dobutamine and particularly dipyridamole stress echocardiography results were associated not only with stenosis severity - percent diameter stenosis (dobutamine, p = 0.04; dipyridamole, p = 0.003) - but also, and even more strongly, with lesion morphology (dobutamine, p = 0.006; dipyridamole, p = 0.0009). As all of stress echocardiography results were significantly associated with percent diameter stenosis, the best angiographic cutoff in relation to the results of stress echocardiography test was: exercise, 54%; dobutamine, 58% and dipyridamole, 60% (p < 0.05 vs. exercise). CONCLUSIONS Integrated evaluation of angiographic variables have shown that the results of dobutamine and dipyridamole stress echocardiography are not only influenced by stenosis severity but also, and even more importantly, by plaque morphology. The results of exercise stress echocardiography, although separately influenced by plaque morphology, are predominantly influenced by stenosis severity, due to a stronger exercise capacity in provoking myocardial ischemia in milder forms of coronary stenosis.

High Dose Adenosine Stress Echocardiography for Noninvasive Detection of Coronary Artery Disease

OBJECTIVES The aim of this study was to assess the tolerability and incremental diagnostic value of high adenosine doses in stress echocardiography testing in patients with coronary artery disease (CAD). BACKGROUND In comparison with other pharmacologic stress echocardiography tests, standard dose adenosine stress has sub-optimal sensitivity for detecting milder forms of CAD. METHODS Adenosine stress echocardiography was performed in 58 patients using a starting dose of 100 micrograms/kg body weight per min over 3 min followed by 140 micrograms/kg per min over 4 min (standard dose). If no new wall motion abnormality appeared, the dose was increased to 200 micrograms/kg per min over 4 min (high dose). All patients underwent coronary angiography. Significant CAD was defined as > or = 50% diameter stenosis in at least one major coronary artery. Thirty-three patients had one-vessel and seven had multivessel CAD. Coronary angiographic findings were normal in 18 patients. RESULTS The high adenosine dose caused a slight but significant increase over baseline values in rate-pressure product. Limiting side effects occurred in two patients during the standard dose protocol and in one patient receiving the high dose regimen. The test was stopped in 30 patients after the standard adenosine dose regimen because of a provoked new wall motion abnormality. The sensitivity of adenosine echocardiography with the standard dose was 75% (95% confidence interval [CI] 63% to 87%). After completion of the standard dose protocol, 28 patients continued testing with the high dose adenosine protocol. The overall sensitivity of adenosine echocardiography, calculated as cumulative, increased to 92% (95% CI 84% to 100%) with the high dose (p < 0.05). The specificity of adenosine testing was 100% and 88%, respectively, with the standard and high dose regimen (p = 0.617). CONCLUSIONS We believe that use of a higher than usual adenosine dose protocol for stress testing may improve the diagnostic value of adenosine echocardiography, mainly by increasing sensitivity in patients with single-vessel disease without deterioration of the safety profile and with only a mild reduction in specificity.

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.