Ana Djordjević Dikić

BACKGROUND: Exercise-based rehabilitation is an important part of treatment patients following coronary artery bypass graft (CABG) surgery. HYPOTHESIS: To evaluate effect of very short/short-term exercise training on cardiopulmonary exercise testing (CPET) parameters. METHODS: We studied 54 consecutive patients with myocardial infarction (MI) treated with CABG surgery referred for rehabilitation. The study population consisted of 50 men and 4 women (age 57.72 ± 7.61 years, left ventricular ejection fraction 55% ± 5.81%), who participated in a 3-week clinical and 6-month outpatient cardiac rehabilitation program. The Inpatient program consisted of cycling 7 times/week and daily walking for 45 minutes. The outpatient program consisted mainly of walking 5 times/week for 45 minutes and cycling 3 times/week. All patients performed symptom-limited CPET on a bicycle ergometer with a ramp protocol of 10 W/minute at the start, for 3 weeks, and for 6 months. RESULTS: (1.48 ± 0.40 vs 1.68 ± 0.43, respectively, P < 0.05), peak ventilatory exchange (44.52 ± 11.32 vs 52.56 ± 12.37 L/min, respectively, P < 0.05), and peak breathing reserve (52.00% ± 13.73% vs 45.75% ± 14.84%, respectively, P < 0.05) were also improved. The same improvement trend continued after 6 months (respectively, P < 0.001 and P < 0.0001). No major adverse cardiac events were noted during the rehabilitation program. CONCLUSIONS: Very short/short-term exercise training in patients with MI treated with CABG surgery is safe and improves functional capacity.

Background Microvascular dysfunction might be a major determinant of clinical deterioration and outcome in patients with hypertrophic cardiomyopathy (HCM). However, long‐term prognostic value of transthoracic Doppler echocardiography (TDE) coronary flow velocity reserve (CFVR) on clinical outcome is uncertain in HCM patients. Therefore, the aim of our study was to assess long‐term prognostic value of CFVR on clinical outcome in HCM population. Methods and Results We prospectively included 150 HCM patients (82 women; mean age 48±15 years). Patients’ clinical characteristics, echocardiographic and CFVR findings (both for left anterior descending [LAD] and posterior descending artery [PD]), were assessed in all patients. The primary outcome was a composite of: HCM related death, heart failure requiring hospitalization, sustained ventricular tachycardia and ischemic stroke. Patients were stratified into 2 subgroups depending on CFVR LAD value: Group 1 (CFVR LAD&gt;2, [n=87]) and Group 2 (CFVR LAD≤2, [n=63]). During a median follow‐up of 88 months, 41/150 (27.3%) patients had adverse cardiac events. In Group 1, there were 8/87 (9.2%), whereas in Group 2 there were 33/63 (52.4%, P &lt;0.001 vs. Group 1) adverse cardiac events. By Kaplan‐Meier analysis, patients with preserved CFVR LAD had significantly higher cumulative event‐free survival rate compared to patients with impaired CFVR LAD (96.4% and 90.9% versus 66.9% and 40.0%, at 5 and 8 years, respectively: log‐rank 37.2, P &lt;0.001). Multivariable analysis identified only CFVR LAD≤2 as an independent predictor for adverse cardiac outcome (HR 6.54; 95% CI 2.83–16.30, P &lt;0.001), while CFVR PD was not significantly associated with outcome. Conclusions In patients with HCM, impaired CFVR LAD (≤2) is a strong, independent predictor of adverse cardiac outcome. When the aim of testing is HCM risk stratification and CFVR LAD data are available, the evaluation of CFVR PD is redundant.

AIMS: The aim of the study was to assess the value of coronary flow reserve (CFR) for predicting improvement of left ventricular function after cardiac resynchronization therapy (CRT). METHODS AND RESULTS: Study population included 40 patients (mean age 58 ± 9 years) with heart failure (ejection fraction 25, 7 ± 5, 4%) and QRS duration of 158 ± 22 ms, planned for CRT. Before and after CRT implantation, CFR was measured non-invasively during hyperaemia induced with adenosine. Responders were defined by decrease in end-systolic volume ≥15%. Follow-up echocardiography and CFR measurements were obtained after 6 months. At baseline there was no significant difference in left ventricular ejection fraction (LVEF), QRS duration, 6 min walk test distance and coronary flow velocity at rest between responder (n = 26) vs. non-responder group (n = 14, P = ns). Before CRT implantation, responders compared with non-responders, showed a greater increase in coronary flow velocity during hyperaemia, and consequently higher CFR: 2.41 ± 0.60 vs. 1.61 ± 0.45 (P = 0.001). There was significant correlation between CFR before CRT implantation and LVEF after 6 months (r = 0.545, P = 0.001). End-diastolic, end-systolic left ventricular diameter, and CFR before CRT were predictors of LV functional improvement. By multivariate analysis, only CFR before CRT was independent predictor of left ventricular recovery in the follow-up period (P = 0.001). CONCLUSION: Our results demonstrate that preserved CFR in patients with dilated cardiomyopathy is predictive of left ventricular improvement after CRT implantation.

OBJECTIVE: The aims of this study were to investigate the incidence and parameters associated with myocardial ischemia during mental stress (MS) as measured by echocardiography and to evaluate the relation between MS-induced and exercise-induced myocardial ischemia. METHODS: Study participants were 79 patients (63 men; mean [M] [standard deviation {SD}] age = 52 [8] years) with angiographically confirmed coronary artery disease and previous positive exercise test result. The MS protocol consisted of mental arithmetic and anger recall task. The patients performed a treadmill exercise test 15 to 20 minutes after the MS task. Data of post-MS exercise were compared with previous exercise stress test results. RESULTS: The frequency of echocardiographic abnormalities was 35% in response to the mental arithmetic task, compared with 61% with anger recall and 96% with exercise (p < .001, exercise versus MS). Electrocardiogram abnormalities and chest pain were substantially less common during MS than were echocardiographic abnormalities. Independent predictors of MS-induced myocardial ischemia were: wall motion score index at rest (p = .02), peak systolic blood pressure (p = .005), and increase in rate-pressure product (p = .004) during MS. The duration of exercise stress test was significantly shorter (p < .001) when MS preceded the exercise and in the case of earlier exercise (M [SD] = 4.4 [1.9] versus 6.7 [2.2] minutes for patients positive on MS and 5.7 [1.9] versus 8.0 [2.3] minutes for patients negative on MS). CONCLUSIONS: Echocardiography can be successfully used to document myocardial ischemia induced by MS. MS-induced ischemia was associated with an increase in hemodynamic parameters during MS and worse function of the left ventricle. MS may shorten the duration of subsequent exercise stress testing and can potentiate exercise-induced ischemia in susceptible patients with coronary artery disease.