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Coronary microvascular dysfunction. An update
No full textSeveral studies in the last years have shown that a dysfunction of coronary microcirculation may be responsible for abnormalities in coronary blood flow and some clinical pictures. Coronary microvascular dysfunction, in absence of other coronary artery abnormalities, can cause anginal symptoms, resulting in a condition named microvascular angina (MVA). MVA can occur in a chronic form, predominantly related to effort (stable MVA), more frequently referred as cardiac syndrome X, or in an acute form, most frequently ensuing at rest, which simulates an acute coronary syndrome (unstable MVA). The main abnormalities characterizing these two forms of MVA consist of an impaired vasodilation and an increased vasoconstriction of small resistive coronary arteries, respectively. The mechanisms responsible for stable MVA are still unclear, but seem to include, together with the known traditional cardiovascular risk factors, an abnormally increased cardiac adrenergic activity. The prognosis of stable MVA is good, but some patients have progressive worsening of symptoms. Clinical outcome of patients with unstable MVA is substantially unknown, as there are no specific studies about this population. Treatment of stable MVA includes traditional anti-ischemic drugs as first step; in case of persisting symptoms several other drugs have been proposed, including xanthine derivatives, ACE-inhibitors, statins and, in women, estrogens. Severe forms of intense constriction (or spasm) of small coronary arteries may cause transmural myocardial ischemia, as the microvascular form of variant angina and the tako-tsubo syndrome
Association of coronary microvascular dysfunction with restenosis of left anterior descending coronary artery disease treated by percutaneous intervention
No full textBackground: Several patients with successful percutaneous coronary interventions (PCIs) show evidence of coronary microvascular dysfunction (CMVD), which can be responsible for persistent positivity of electrocardiographic exercise stress test (EST). In this study, we assessed whether post-PCI CMVD may predict clinical outcome in patients undergoing successful elective PCI of an isolated stenosis of the left anterior descending (LAD) coronary artery.
Methods: We studied 29 patients (age 64 +/- 6, 23 M) with stable coronary artery disease and isolated stenosis (>75%) of the LAD coronary artery who underwent successful PCI with stent implantation. Coronary blood flow (CBF) velocity response to adenosine and to cold-pressor test (CPT) was assessed in the LAD coronary artery by transthoracic Doppler echocardiography 24 h and 3 months after PCI. The primary end-point was a combination of death, admission for acute coronary syndromes (ACS) or target vessel revascularization (TVR).
Results: No death or ACS occurred during 36 months of follow-up, but TVR was performed in 5 patients (17.2%). CBF response to CPT at 3 months after PCI was 1.31 +/- 0.2 vs. 1.71 +/- 0.4 in patients with or without TVR, respectively (p = 0.03), whereas CBF response to adenosine at 3 months in these two groups was 1.70 +/- 0.3 vs. 2.05 +/- 0.4 (p = 0.059).
Conclusions: Our data suggest that, in patients with successful PCI of LAD coronary artery stenosis, lower CBF response to the endothelium-dependent vasodilator stimulus CPT is associated with long-term recurrence of restenosis
Microvascular angina: ― Long-term exercise stress test follow-up ―
No full textBackground: A sizeable proportion of patients with primary stable microvascular angina (MVA; exercise-induced angina, positive exercise stress test [EST], normal coronary arteries) have recurrent symptoms during follow-up. There have been no previous studies, however, on the long-term results of EST and their correlation with symptom outcome. Methods and Results: Follow-up EST was performed in 71 MVA patients at an average of 16.2 years (range, 5–25 years) from the first EST. Angina status was assessed on weekly frequency of angina episodes and nitroglycerin consumption and by whether symptoms had worsened, improved, or remained unchanged over time. At follow-up EST, 41 patients (group 1) had exercise-induced ischemia, whereas 30 patients (group 2) had negative EST. Compared to group 2, group 1 patients more frequently had exercise-induced dyspnea, and had a greater maximum ST-segment depression and a lower coronary blood flow response to adenosine and cold pressor test, but group 2 patients had a more frequent history of rest angina. No differences between the 2 groups were found at follow-up in angina status or change in symptom status during follow-up. Conclusions: Electrocardiogram results improve significantly in a sizeable proportion of patients with MVA. Changes in EST results, however, were not associated with clinical outcome
Coronary microvascular dysfunction in patients with acute coronary syndrome and non-obstructive coronary artery disease: a 10-year clinical follow-up study
No full textBackground and methods: Previous studies suggested that patients with myocardial infarction and non-obstructive coronary arteries (MINOCA) may have adverse clinical outcomes, but long-term follow-up has not hitherto been investigated. In this study we assessed whether non-invasive assessment of coronary functional abnormalities may help predicting long-term prognosis. We assessed coronary blood flow velocity (CBFV) response to ergonovine, adenosine and cold pressor test (CPT) by transthoracic Doppler echocardiography and performed exercise stress test (EST) in 30 patients (67 ± 10 years, 19 female) with MINOCA and 10 patients with non-cardiac acute chest pain (control group). Clinical conditions were assessed at a median follow-up of 10.3 years (interquartile interval, 8.4-10.5). Clinical endpoints included major adverse cardiovascular events (MACE) and all-cause mortality. Results: MACE occurred in 10 patients (33.3 %) and 1 control (9.1 %) (HR 4.20, 95 % C.I. 0.54-32.9, p = 0.17). Death occurred in 6 MINOCA patients (20 %), mainly from non-cardiovascular causes, whereas no death occurred in the control group (p = 0.37). In MINOCA patients, CBFV response to CPT was significantly associated with all-cause mortality (p = 0.046), whereas age (p = 0.084), CBFV response to adenosine (p = 0.096) and EST duration (p = 0.099) were of borderline statistical significance. At multivariable analysis, EST duration emerged as the only independent variable associated with mortality (p = 0.041). No variable was found to be predictive of long-term MACE in MINOCA patients. Conclusions: MINOCA patients present a sizeable global, but low cardiovascular mortality at long-term follow-up. Functional capacity seems the only variable independently predictive of global mortality, whereas non-invasive coronary functional tests seem unable to predict mortality and MACE
Long-term prognosis of patients with cardiac syndrome X
No full textBACKGROUND: Previous follow-up studies of patients with cardiac syndrome X (CSX) reported good prognosis. However, some recent reports challenged this finding by showing appreciable mortality rates in patients with angina and normal coronary arteries admitted for acute coronary syndromes.
METHODS: We performed clinical follow-up of 155 patients (mean age 58.9+/-10 years, 40 men) with typical CSX. The occurrence of major cardiac events (cardiac death, acute myocardial infarction), readmission for chest pain, revascularization procedures, angina status, and non cardiac events during follow-up were collected for each patient.
RESULTS: At a mean follow-up time of 137+/-78 months (range 24-372) from the onset of symptoms, 4 patients died, 3 for cancers and 1 for acute pancreatitis. No patient died from cardiovascular causes or had any major cardiovascular event. Hospital readmission for recurrent chest pain was reported by 89 patients (58%), and 33 (22%) underwent at least one more coronary angiography. During follow-up, chest pain had remained unchanged in 33% of patients and had worsened in 14% of patients.
CONCLUSION: Our data show that patients with CSX have excellent long-term clinical prognosis. A significant number of patients, however, shows persistence or worsening of symptoms, as well as further recurrence to medical evaluation
Long-term effects of bariatric surgery on peripheral endothelial function and coronary microvascular function
No full textBackground We previously demonstrated that bariatric surgery (BS) leads to a short-term significant improvement of endothelial function and coronary microvascular function. In this study we assessed whether BS maintains its beneficial effect at long-term follow up. Design We studied 19 morbidly obese patients (age 43 ± 9 years, 12 women) without any evidence of cardiovascular disease who underwent BS. Patients were studied before BS, at 3 months and at 4.0 ± 1.5 years follow up. Methods Peripheral vascular function was assessed by flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD), i.e., brachial artery diameter changes in response to post-ischemic forearm hyperhaemia and to nitroglycerin administration, respectively. Coronary microvascular function was assessed by measuring coronary blood flow (CBF) response to intravenous adenosine and to cold pressor test (CPT) in the left anterior descending coronary artery. Results Together with improvement of anthropometric and metabolic profile, at long-term follow-up patients showed a significant improvement of FMD (6.43 ± 2.88 vs. 8.21 ± 1.73%, p = 0.018), and CBF response to both adenosine (1.73 ± 0.48 vs. 2.58 ± 0.54; p < 0.01) and CPT (1.43 ± 0.30 vs. 2.23 ± 0.48; p < 0.01), compared to basal values. No differences in vascular end-points were shown at 3-month and 4-year follow-up after BS. Conclusions Our data show that, in morbidly obese patients, BS exerts beneficial and long lasting effects on peripheral endothelial function and on coronary microvascular dilator function
Effect of smoking on endothelium-independent vasodilatation
No full textSmoking induces an impairment of endothelium-dependent vasodilatation. In this study we assessed whether smoking also causes an impairment of endothelium-independent vasodilatation
Lack of Effect of Nitrates on Exercise Stress Test Results in Patients with Microvascular Angina
No full textPURPOSE: To assess the effects of short-acting nitrates on exercise stress test (EST) results and the relation between EST results and coronary blood flow (CBF) response to nitrates in patients with microvascular angina (MVA). METHODS: We completed 2 symptom/sign limited ESTs on 2 separate days, in a random sequence and in pharmacological washout, in 29 MVA patients and in 24 patients with obstructive coronary artery disease (CAD): one EST was performed without any intervention (control EST, C-EST), and the other after sublingual isosorbide dinitrate, 5 mg (nitrate EST, N-EST). CBF response to nitroglycerin (25 μg) was assessed in the left anterior descending coronary artery by transthoracic Doppler-echocardiography. RESULTS: At C-EST. ST-segment depression ≥1 mm (STD) was induced in 26 (90 %) and 23 (96 %) MVA and CAD patients, respectively (p = 0.42), whereas at N-EST, STD was induced in 25 (86 %) and 14 (56 %) MVA and CAD patients, respectively (p = 0.01). Time and rate pressure product at 1 mm STD increased during N-EST, compared to C-EST, in CAD patients (475 ± 115 vs. 365 ± 146 s, p < 0.001; and 23511 ± 4352 vs. 20583 ± 6234 bpm[Symbol: see text]mmHg, respectively, p = 0.01), but not in MVA patients (308 ± 160 vs. 284 ± 136 s; p = 0.19; and 21290 ± 5438 vs. 20818 ± 4286 bpm[Symbol: see text]mmHg, respectively, p = 0.35). In MVA patients, a significant correlation was found between heart rate at STD during N-EST and CBF response to nitroglycerin (r = 0.40, p = 0.04). CONCLUSIONS: Short-acting nitrates improve EST results in CAD, but not in MVA patients. In MVA patients a lower nitrate-dependent coronary microvascular dilation may contribute to the lack of effects of nitrates on EST results
Effect of ranolazine on arterial endothelial function in patients with type 2 diabetes mellitus
No full textTo assess the effect of ranolazine on systemic vascular function in patients with type II diabetes mellitus (T2DM)
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