Noninvasive evaluation of dynamic microvascular dysfunction in ischemia and no obstructive coronary artery disease patients with suspected vasospasm.

INTRODUCTION: In patients with ischemia and no obstructive coronary artery disease (INOCA), a dynamic coronary microvascular dysfunction (CMD) is frequent but difficult to capture by noninvasive means.The aim of our study was to assess dynamic CMD in INOCA patients with stress echocardiography after vasoconstrictive and vasodilator stimuli. METHODS: In this prospective single-center study, we have enrolled 40 INOCA patients (age 56.3 ±â€Š13 years, 32 women). All participants underwent stress echocardiography with hyperventilation (HYP), followed by supine bicycle exercise (HYP+EXE) and adenosine (ADO). Stress echocardiography included an assessment of regional wall motion abnormality (RWMA) and coronary flow velocity (CFV) in the distal left anterior descending (LAD) coronary artery. RESULTS: HYP induced a 30% increase in rate pressure product (rest = 10 244 ±â€Š2353 vs. HYP = 13 214 ±â€Š3266 mmHg x bpm, P  < 0.001) accompanied by a paradoxical reduction in CFV (HYP< rest) in 21 patients (52%). HYP alone was less effective than HYP+EXE in inducing anginal pain (6/40, 15% vs. 10/40, 25%, P  = 0.046), ST segment changes (6/40, 15% vs. 24/40, 60%, P  < 0.001), and RWMA (6/40, 15% vs. 13/40, 32.5%, P  = 0.008). ADO-induced vasodilation was preserved (≥2.0) in all patients. CONCLUSION: In patients with INOCA, a coronary vasoconstriction after HYP is common, in absence of structural CMD detectable with ADO. HYP+EXE test represents a more powerful ischemia inducer than HYP alone. Stress echocardiography with LAD-CFV may allow the noninvasive assessment of dynamic and structural coronary microcirculation during stress.

Pulmonary congestion during Exercise stress Echocardiography in Hypertrophic Cardiomyopathy.

BACKGROUND: B-lines detected by lung ultrasound (LUS) during exercise stress echocardiography (ESE), indicating pulmonary congestion, have not been systematically evaluated in patients with hypertrophic cardiomyopathy (HCM). AIM: To assess the clinical, anatomical and functional correlates of pulmonary congestion elicited by exercise in HCM. METHODS: We enrolled 128 HCM patients (age 52 ± 15 years, 72 males) consecutively referred for ESE (treadmill in 46, bicycle in 82 patients) in 10 quality-controlled centers from 7 countries (Belgium, Brazil, Bulgaria, Hungary, Italy, Serbia, Spain). ESE assessment at rest and peak stress included: mitral regurgitation (MR, score from 0 to 3); E/e'; systolic pulmonary arterial pressure (SPAP) and end-diastolic volume (EDV). Change from rest to stress was calculated for each variable. Reduced preload reserve was defined by a decrease in EDV during exercise. B-lines at rest and at peak exercise were assessed by lung ultrasound with the 4-site simplified scan. B-lines positivity was considered if the sum of detected B-lines was ≥ 2. RESULTS: LUS was feasible in all subjects. B-lines were present in 13 patients at rest and in 38 during stress (10 vs 30%, p < 0.0001). When compared to patients without stress B-lines (n = 90), patients with B-lines (n = 38) had higher resting E/e' (14 ± 6 vs. 11 ± 4, p = 0.016) and SPAP (33 ± 10 vs. 27 ± 7 mm Hg p = 0.002). At peak exercise, patients with B-lines had higher peak E/e' (17 ± 6 vs. 13 ± 5 p = 0.003) and stress SPAP (55 ± 18 vs. 40 ± 12 mm Hg p < 0.0001), reduced preload reserve (68 vs. 30%, p = 0.001) and an increase in MR (42 vs. 17%, p = 0.013) compared to patients without congestion. Among baseline parameters, the number of B-lines and SPAP were the only independent predictors of exercise pulmonary congestion. CONCLUSIONS: Two-thirds of HCM patients who develop pulmonary congestion on exercise had no evidence of B-lines at rest. Diastolic impairment and mitral regurgitation were key determinants of pulmonary congestion during ESE. These findings underscore the importance of evaluating hemodynamic stability by physiological stress in HCM, particularly in the presence of unexplained symptoms and functional limitation.

Very short/short-term benefit of inpatient/outpatient cardiac rehabilitation programs after coronary artery bypass grafting surgery.

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: After 3 weeks of an exercise-based cardiac rehabilitation program, exercise tolerance improved as compared to baseline, as well as peak respiratory exchange ratio. Most importantly, peak VO2 (16.35 ± 3.83 vs 17.88 ± 4.25 mL/kg/min, respectively, P < 0.05), peak VCO2 (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.

Prognostic role of stress echocardiography in hypertrophic cardiomyopathy: The International Stress Echo Registry.

BACKGROUND: Stress echo (SE) may have a role in the outcome in patients with hypertrophic cardiomyopathy (HCM). OBJECTIVES: The aim was to assess the prognostic value of SE in a retrospective multicenter study in HCM. METHODS: We enrolled 706 HCM patients. The employed stress was exercise (n=608) and/or vasodilator (n=146, dipyridamole in 98 and adenosine in 48). We defined SE positivity according to clinical/hemodynamic criteria including: symptoms (all stress modalities), exercise-induced hypotension (failure to increase or fall >20mmHg, exercise) and exercise-induced left ventricular outflow tract obstruction (left ventricular outflow tract obstruction >50mmHg); and ischemic criteria, such as new wall motion abnormalities (new wall motion abnormality) and/or reduction of coronary flow reserve velocity (CFVR≤2.0) on left anterior descending coronary artery with vasodilator stress assessed in 116 patients. All patients completed the clinical follow-up. RESULTS: Positive SE showed more frequently CFVR reduction, exercise-induced hypotension, left ventricular outflow tract obstruction, and symptoms (38, 23, 20 and 15% respectively), but new wall motion abnormality only in 6%. During a median follow-up of 49months 180 events were observed, including 40 deaths. Clinical/hemodynamic criteria did not predict outcome (X2 0.599, p=0.598), whereas ischemia-related SE criteria (X2: 111.120, p<0.0001) was significantly related to outcome. Similarly, mortality was predicted with SE ischemic-criteria (X2 16.645, p<0.0001). CONCLUSIONS: SE has an important prognostic significance in HCM patients, with ischemia-related end-points showing greater predictive accuracy than hemodynamic endpoints. New wall motion abnormalities and impairment of CFVR should be specifically included in SE protocols for HCM.

Mental stress-induced ischemia in patients with coronary artery disease: echocardiographic characteristics and relation to exercise-induced ischemia.

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.