Assessment of the Ischaemic Effects of Myocardial Bridge by Echocardiographic Exercise Stress Test.

Background: Detection of myocardial bridge (MB) at angiography suggests it has a role in ischaemic-related symptoms in patients with angina without obstructive coronary artery disease. However, evidence that MB may cause myocardial ischaemia is limited. Methods: We studied 41 patients with MB of the left anterior descending coronary artery and otherwise normal coronary arteries. Fourteen patients with normal coronary arteries and without MB served as controls. All subjects underwent a maximal treadmill exercise stress test (EST) under ECG monitoring. Standard and speckle-tracking echocardiography were performed at baseline and immediately after peak EST. Results: EST duration and peak heart rate and systolic pressure were similar in the two groups. A positive EST (ST-segment depression .1 mm) was found in 18 patients in the MB group (43.9%) and none in the control group (p=0.001). No abnormalities in both left ventricle systolic and diastolic function were found between the two groups in the standard echocardiographic evaluation. Global and segmental (anterior, inferior) longitudinal strain (LS) did not differ at baseline between the groups. There was a small increase in global LS during EST in MB patients but not in the control group (p=0.01). Similar trends were found for regional LSs, with differences being significant for the medium (p=0.028) and apical (p=0.032) anterior segments. No differences in echocardiographic parameters and both global and segmental LSs were observed between MB patients with ischaemic ECG changes during EST versus those without. Conclusion: Our findings do not support the notion that MB results in significant degrees of myocardial ischaemia during maximal myocardial work.

Comparison of Baseline and Post-Nitrate Exercise Testing in Patients with Angina but Non-Obstructed Coronary Arteries with Different Acetylcholine Test Results.

Background: Intracoronary acetylcholine testing may induce epicardial coronary artery spasm (CAS) or coronary microvascular spasm (CMVS) in patients with angina syndromes but non-obstructive coronary artery disease, but their causal role in individual patients is not always clear. In this prospective, observational single-center study, we aimed to assess whether (1) the induction of myocardial ischemia/angina by electrocardiogram (ECG) exercise stress test (EST) differs between patients showing different results in response to acetylcholine testing (i.e., CAS, CMVS, or no spasm); (2) the preventive administration of short-acting nitrates has any different effects on the EST of those patients who showed a positive basal EST. We expected that if exercise-induced angina and/or ischemic ECG changes are related to CAS, they should improve after nitrates administration, whereas they should not significantly improve if they are caused by CMVS. Methods: We enrolled 81 patients with angina syndromes and non-obstructive coronary artery disease, who were divided into three groups according to acetylcholine testing: 40 patients with CAS (CAS-group), 14 with CMVS (CMVS-groups), and 27 with a negative test (NEG-group). All patients underwent a basal EST (B-EST). Patients with a positive B-EST repeated the test 24-48 h later, 5 min after the administration of short-acting nitrates (N-EST). Results: There were no significant differences among the groups in terms of the B-EST results. B-EST was positive in eight (20%) patients in the CAS-group, seven (50%) in the CMVS-group, and six (22%) in the NEG-group (p = 0.076). N-EST, performed in eight, six, and five of these patients, also showed similar results in the three groups. Furthermore, the N-EST results also did not significantly differ compared to B-EST in any group, remaining positive in seven (87.5%), four (66.7%), and four (80%) patients in the CAS-group, CMVS-group, and NEG-group, respectively (p = 0.78). Conclusions: Our data show that patients with angina and non-obstructive coronary artery disease show largely comparable results of the ECG exercise stress test and similar poor effects of short-acting nitrates on abnormal ECG exercise stress test results. On the whole, our findings suggest caution in attributing to the results of Ach testing a definite causal role for the clinical syndrome in individual patients.

Impact on clinical outcome of ventricular arrhythmias in patients undergoing transcatheter aortic valve implantation.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) has become a largely used treatment for severe aortic stenosis. There are limited data, however, about predictors of long-term prognosis in this population. In this study, we assessed whether ventricular arrhythmias may predict clinical outcomes in patients undergoing TAVI. METHODS AND RESULTS: We performed a 24 h ECG Holter monitoring in 267 patients who underwent TAVI for severe aortic stenosis within 30 days from a successful procedure. The occurrence of frequent premature ventricular complexes (PVCs; ≥30/h), polymorphic PVCs and nonsustained ventricular tachycardia (NSVT) was obtained for each patient. Clinical outcome was obtained for 228 patients (85%), for an average follow-up of 3.5 years (range 1.0-8.6). Cardiovascular events (CVEs; cardiovascular death or resuscitated cardiac arrest) occurred in 26 patients (11.4%) and 63 patients died (27.6%). Frequent PVCs but not polymorphic PVCs and NSVT were found to be associated with CVEs at univariate analysis. Frequent PVCs were indeed found in 12 patients with (46.2%) and 35 without (17.3%) CVEs [hazard ratio 2.30; 95% confidence interval (CI) 1.03-5.09; P  = 0.04], whereas polymorphic PVCs were found in 11 (42.3%) and 54 (26.7%) patients of the two groups, respectively (hazard ratio 1.44; 95% CI 0.64-3.25; P  = 0.38), and NSVT in 9 (34.6%) and 43 patients of the two groups, respectively (hazard ratio 1.18; 95% CI 0.48-2.87; P  = 0.72). Frequent PVCs, however, were not significantly associated with CVEs at multivariate Cox regression analysis (hazard ratio 1.53; 95% CI 0.37-6.30; P  = 0.56). Both frequent PVCs, polymorphic PVCs and NSVT showed no significant association with mortality. CONCLUSION: In our study, the detection of frequent PVCs at Holter monitoring after TAVI was a predictor of CVEs (cardiovascular death/cardiac arrest), but this association was lost in multivariable analysis.

The Impact of Climate Change and Extreme Weather Conditions on Cardiovascular Health and Acute Cardiovascular Diseases.

Climate change is widely recognized as one of the most significant challenges facing our planet and human civilization. Human activities such as the burning of fossil fuels, deforestation, and industrial processes release greenhouse gases into the atmosphere, leading to a warming of the Earth's climate. The relationship between climate change and cardiovascular (CV) health, mediated by air pollution and increased ambient temperatures, is complex and very heterogeneous. The main mechanisms underlying the pathogenesis of CV disease at extreme temperatures involve several regulatory pathways, including temperature-sympathetic reactivity, the cold-activated renin-angiotensin system, dehydration, extreme temperature-induced electrolyte imbalances, and heat stroke-induced systemic inflammatory responses. The interplay of these mechanisms may vary based on individual factors, environmental conditions, and an overall health background. The net outcome is a significant increase in CV mortality and a higher incidence of hypertension, type II diabetes mellitus, acute myocardial infarction (AMI), heart failure, and cardiac arrhythmias. Patients with pre-existing CV disorders may be more vulnerable to the effects of global warming and extreme temperatures. There is an urgent need for a comprehensive intervention that spans from the individual level to a systemic or global approach to effectively address this existential problem. Future programs aimed at reducing CV and environmental burdens should require cross-disciplinary collaboration involving physicians, researchers, public health workers, political scientists, legislators, and national leaders to mitigate the effects of climate change.

Insulin pump treatment vs. multiple daily insulin injections in patients with poorly controlled Type 2 diabetes mellitus: a comparison of cardiovascular effects.

AIMS: Both hyperglycaemia and large glycaemic variability are associated with worse outcomes in patients with Type 2 diabetes mellitus (T2DM), possibly causing sympatho-vagal imbalance and endothelial dysfunction. Continuous subcutaneous insulin injection (CSII) improves glycemic control compared to multiple daily insulin injections (MDI). We aimed to assess whether CSII may improve cardiac autonomic and vascular dilation function compared to MDI. METHODS: We enrolled T2DM patients without cardiovascular disease with poor glycaemic control, despite optimized MDI therapy. Patients were randomized to continue MDI (with multiple daily peripheral glucose measurements) or CSII; insulin dose was adjusted to achieve optimal target ranges of blood glucose levels. Patients were studied at baseline and after 6 months by: 1) flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD) of the brachial artery; 2) heart rate variability (HRV) by 24-hour ECG Holter monitoring (HM). 7-day continuous glucose monitoring (CGM) was performed in 9 and 8 patients of Group 1 and 2, respectively. RESULTS: Overall, 21 patients were enrolled, 12 randomized to CSII (Group 1) and 9 to MDI (Group 2). The daily dose of insulin and Hb1AC did not differ significantly between the 2 groups, both at baseline and at follow-up. Glucose variability showed some significant improvement at follow-up in the whole population, but no differences were observed between the 2 groups. Both FMD and NMD, as well as HRV parameters, showed no significant differences between the 2 groups at 6-month follow-up. CONCLUSIONS: In this randomized small study we show that, in T2DM patients, CSII achieves a similar medium-term glycemic control compared to MDI, without any adverse effect on the cardiovascular system.

Relation between high-sensitivity troponin I serum levels and myocardial ischemia in patients with suspected chronic coronary syndrome: The reset-MI study.

BACKGROUND: Previous studies showed that exercise may increase cardiac troponin serum levels; whether the occurrence of myocardial ischemia influences the changes of exercise-induced troponin raise, however, remains debatable. METHODS: We prospectively enrolled consecutive patients undergoing for the first time an elective stress myocardial perfusion scintigraphy (MPS) because of clinical suspicion of obstructive coronary artery disease (CAD). Patients were divided into 3 groups based on the evidence and degree of stress-induced myocardial ischemia at MPS: 1) group 1, no myocardial ischemia (≤4 %); 2) group 2, mild myocardial ischemia (5-10 %); 3) group 3, moderate-to-severe myocardial ischemia (≥10 %). High-sensitivity cardiac troponin I (cTnI) was measured immediately before (T0) and 1 hour (T1) and 4 h (T2) after the stress test. RESULTS: One hundred-seven patients (71 males; age 65.6 ± 9.4 years) were enrolled in the study. Serum hs-cTnI concentrations (logarithmic values) significantly increased after MPS, compared to baseline, in the whole population, from 1.47±1.26 ng/L at T0, to 1.68±1.12 ng/L at T1 (p<0.001) and 2.15±1.02 ng/L at T2 (p<0.001 vs. both T0 and T1). The increase in hs-cTnI did not significantly differ between the 3 groups (p = 0.44). The heart rate achieved during the test was the strongest determinant of cTnI increase (p < 0.001) after the stress test. CONCLUSIONS: In patients with suspected CAD, stress MPS induces an increase of cTnI that is independent of the induction and extension/severity of myocardial ischemia and is mainly related to myocardial work, as indicated by the heart rate achieved during the test.

Prognostic Assessment of Early Repolarization/J Wave Electrocardiographic Pattern in Patients With Stable Ischemic Heart Disease.

Recent studies suggested that early repolarization (ER)/J wave at the electrocardiogram (ECG) is associated with increased risk of sudden death and ventricular arrhythmias in patients with acute myocardial infarction. In this study, we prospectively assessed whether ER/J wave has any long-term prognostic implications in patients with stable ischemic heart disease (IHD). We enrolled consecutive clinically stable patients with documented IHD, referred to undergo a routine ECG. ER (typical concave ST-segment elevation) and J wave were diagnosed according to prospectively defined criteria. The final population included 617 patients with documented IHD (455 men; age 68.1 ± 11 years). ER/J wave was found in 138 patients (22.4%), 13 of whom (2.1%) showed ER and 133 (21.6%) a J wave. At a follow-up of 8.1±2.9 years, 160 deaths occurred (25.9%), 60 (9.7%) attributed to cardiovascular causes. Total mortality was lower in patients with versus those without ER/J wave (18.8% vs 28.0%; hazard ratio [HR] 0.61, 95% confidence interval [CI] 0.40 to 0.93, p = 0.02). The difference, however, was not significant after adjustment for confounding clinical variables (HR 0.78, 95% CI 0.51 to 1.19, p = 0.25). No significant difference was found in cardiovascular death between patients with (7.2%) and those without (10.4%) ER/J wave (adjusted HR 0.78, 95% CI 0.40 to 1.55, p = 0.48). Similar results were obtained for ER and J wave separately, and for ECG location of ER/J wave (inferior or lateral/precordial) and type of J wave (notched or slurred). The ER/J wave pattern at the ECG is not associated with increased risk of long-term mortality in clinically stable patients with a documented history of IHD.

Clinical features and outcomes of patients with stable or unstable chest pain and no-obstructive coronary artery disease.

Background: Coronary microvascular dysfunction can be responsible for both stable angina and acute coronary syndrome (ACS). There are scarce data, however, about comparisons of clinical characteristics and outcomes of these 2 groups of patients. Materials and methods: We studied 47 consecutive patients who underwent coronary angiography for angina syndromes and showed no obstructive stenosis. Patients were divided in 2 groups, according to their clinical presentation, i.e., stable angina (n = 21) or non-ST segment elevation ACS (NSTE-ACS; n = 26). An intracoronary acetylcholine (Ach) test was performed in 12 and 17 patients of the 2 groups, respectively. Angina status, assessed by Seattle Angina Questionnaire (SAQ), and clinical events were assessed after 1, 6, and 30 months. An exercise stress test was performed 1 month after discharge. Results: Clinical characteristics and exercise test results of the 2 groups were largely similar. Ach testing induced epicardial or microvascular spasm in 6 (50.0%) and 10 (58.8%) stable and NSTE-ACS patients, respectively (p = 0.72). Stable patients reported higher rates of angina, compared to NSTE-ACS patients, both at 1 (p = 0.04) and 30 months (81 vs. 50%, p = 0.036) of follow-up. SAQ scores were also lower in stable vs. NSTE-ACS patients. Ach testing results showed no association with clinical outcomes. Conclusion: Clinical characteristics and exercise and Ach testing results are similar in angina patients with no-obstructive coronary artery disease with a stable or NSTE-ACS presentation. Stable patients show a worse symptomatic outcome irrespective of Ach test results.

Relation of endothelial and cardiac autonomic function with left ventricle diastolic function in patients with type 2 diabetes mellitus.

BACKGROUND AND AIMS: Diabetes mellitus (DM) is a risk factor for left ventricle (LV) diastolic dysfunction. Aim of this study was to investigate whether endothelial and/or autonomic dysfunction are associated with LV diastolic dysfunction in DM patients. METHODS: We studied 84 non-insulin-dependent type 2 DM (T2DM) patients with no heart disease by assessing: 1) LV diastolic function by echocardiography; 2) peripheral vasodilator function, by measuring flow-mediated dilation (FMD) and nitrate-mediate dilation (NMD); 3) heart rate variability (HRV) on 24-h Holter electrocardiographic monitoring. RESULTS: Twenty-five patients (29.8%) had normal LV diastolic function, while 47 (55.9%) and 12 (14.3%) showed a mild and moderate/severe diastolic dysfunction, respectively. FMD in these 3 groups was 5.25 ± 2.0, 4.95 ± 1.6 and 4.43 ± 1.8% (p = 0.42), whereas NMD was 10.8 ± 2.3, 8.98 ± 3.0 and 8.82 ± 3.2%, respectively (p = 0.02). HRV variables did not differ among groups. However, the triangular index tended to be lower in patients with moderate/severe diastolic dysfunction (p = 0.09) and a significant correlation was found between the E/e' ratio and both the triangular index (r = -0.26; p = 0.022) and LF amplitude (r = -0.29; p = 0.011). CONCLUSIONS: In T2DM patients an impairment of endothelium-independent, but not endothelium-dependent, dilatation seems associated with LV diastolic dysfunction. The possible role of cardiac autonomic dysfunction in diastolic dysfunction deserves investigation in larger populations of patients.

Relation of vascular dilator function and cardiac autonomic function with coronary angiography findings in patients with non-ST segment elevation acute coronary syndrome.

BACKGROUND: A sizeable number of patients with a diagnosis of non-ST segment elevation acute coronary syndrome show non-obstructive coronary artery disease. In this study we assessed whether differences in vascular and cardiac autonomic function exist between non-ST segment elevation acute coronary syndrome patients with obstructive or non-obstructive coronary artery disease. METHODS AND RESULTS: Systemic endothelium-dependent and independent vascular dilator function (assessed by flow-mediated dilation and nitrate-mediated dilation of the brachial artery, respectively) and cardiac autonomic function (assessed by time-domain and frequency-domain heart rate variability parameters) were assessed on admission in 120 patients with a diagnosis of non-ST segment elevation acute coronary syndrome. Patients were divided into two groups according to coronary angiography findings: (a) 59 (49.2%) with obstructive coronary artery disease (≥50% stenosis in any epicardial arteries); (b) 61 (50.8%) with non-obstructive coronary artery disease. No significant differences between the two groups were found in both flow-mediated dilation (5.03 ± 2.6 vs. 5.40 ± 2.5%, respectively; P = 0.37) and nitrate-mediated dilatation (6.79 ± 2.8 vs. 7.30 ± 3.4%, respectively; P = 0.37). No significant differences were also observed between the two groups both in time-domain and frequency-domain heart rate variability variables, although the triangular index tended to be lower in obstructive coronary artery disease patients (30.2 ± 9.5 vs. 33.9 ± 11.6, respectively; P = 0.058). Neither vascular nor heart rate variability variables predicted the recurrence of angina, requiring emergency room admission or re-hospitalisation, during 11.3 months of follow-up. CONCLUSIONS: Among patients admitted with a diagnosis of non-ST segment elevation acute coronary syndrome we found no significant differences in systemic vascular dilator function and cardiac autonomic function between those with obstructive coronary artery disease and those with non-obstructive coronary artery disease.

Relation of vascular dilator function and cardiac autonomic function with coronary angiography findings in patients with non-ST segment elevation acute coronary syndrome.

BACKGROUND: A sizeable number of patients with a diagnosis of non-ST segment elevation acute coronary syndrome show non-obstructive coronary artery disease. In this study we assessed whether differences in vascular and cardiac autonomic function exist between non-ST segment elevation acute coronary syndrome patients with obstructive or non-obstructive coronary artery disease. METHODS AND RESULTS: Systemic endothelium-dependent and independent vascular dilator function (assessed by flow-mediated dilation and nitrate-mediated dilation of the brachial artery, respectively) and cardiac autonomic function (assessed by time-domain and frequency-domain heart rate variability parameters) were assessed on admission in 120 patients with a diagnosis of non-ST segment elevation acute coronary syndrome. Patients were divided into two groups according to coronary angiography findings: (a) 59 (49.2%) with obstructive coronary artery disease (≥50% stenosis in any epicardial arteries); (b) 61 (50.8%) with non-obstructive coronary artery disease. No significant differences between the two groups were found in both flow-mediated dilation (5.03 ± 2.6 vs. 5.40 ± 2.5%, respectively; P = 0.37) and nitrate-mediated dilatation (6.79 ± 2.8 vs. 7.30 ± 3.4%, respectively; P = 0.37). No significant differences were also observed between the two groups both in time-domain and frequency-domain heart rate variability variables, although the triangular index tended to be lower in obstructive coronary artery disease patients (30.2 ± 9.5 vs. 33.9 ± 11.6, respectively; P = 0.058). Neither vascular nor heart rate variability variables predicted the recurrence of angina, requiring emergency room admission or re-hospitalisation, during 11.3 months of follow-up. CONCLUSIONS: Among patients admitted with a diagnosis of non-ST segment elevation acute coronary syndrome we found no significant differences in systemic vascular dilator function and cardiac autonomic function between those with obstructive coronary artery disease and those with non-obstructive coronary artery disease.