Effects of type 2 diabetes mellitus on coronary microvascular function and myocardial perfusion in patients without obstructive coronary artery disease.

PURPOSE: We assessed the impact of type 2 diabetes, in the presence of other major cardiovascular risk factors, on coronary microvascular function and myocardial perfusion in patients without obstructive coronary artery disease (CAD). METHODS: In this prospective study, 23 patients with type 2 diabetes and 26 nondiabetic patients matched for age, sex and other cardiovascular risk factors underwent a cold pressure test (CPT) and dipyridamole transthoracic echocardiography to determine their coronary flow (CF) ratio. Within 2 weeks, all diabetic patients also underwent dipyridamole-rest myocardial perfusion single-photon emission (MPS) CT. None of the patients with or without diabetes had significant CAD on invasive coronary angiography. RESULTS: The CPT-CF ratio was significantly lower in diabetic patients than in nondiabetic patients (1.46 ± 0.26 vs. 1.71 ± 0.32, p = 0.006) and was correlated significantly with fasting glycaemia (r = -0.35, p = 0.01), but not with glycated haemoglobin. The dipyridamole-CF ratio was also lower in diabetic patients than in nondiabetic patients (2.38 ± 0.74 vs. 2.75 ± 0.49, p = 0.04). On MPS imaging, 5 diabetic patients (22%) had stress-induced ischaemia and the remaining 18 (78%) had normal myocardial perfusion. The dipyridamole-CF ratio was not different in patients with and without reversible defects (2.3 ± 1.1 vs. 2.4 ± 0.6, p = 0.97). CONCLUSION: Coronary microvascular function is impaired in type 2 diabetic patients without significant CAD, compared to nondiabetic patients with similar other cardiovascular risk factors. In the majority of diabetic patients, microvascular dysfunction is associated with normal myocardial perfusion.

[Endothelial dysfunction in type 2 diabetic patients with normal coronary arteries. A peripheral arterial tonometry study]. / Evidenza di disfunzione endoteliale in pazienti diabetici di tipo 2 con arterie coronariche angiograficamente normali. Studio con tonometria arteriosa digitale.

AIM: to evaluate endothelial function (EF) in diabetic and non-diabetic patients without CAD by peripheral artery tonometry (PAT) technique. METHODS: a cohort of 94 patients (55 men and 39 postmenopausal women; mean age 63 +/- 9 years) undergoing coronary angiography was divided into 2 groups: 58 patients with DM and (group 1) and 36 patients without DM. Endothelial dysfunction (ED) was assessed by digital pulse amplitude, using a fingertip peripheral arterial tonometry (PAT). As a measure of ED, reactive hyperemia index (RHI) was calculated as the ratio of the digital pulse volume during reactive hyperemia following 5 min ischemia and its basal value. RESULTS: prevalence of cardiovascular risk factors was similar between the two groups. RHI values were significantly lower in diabetic patients compared to non-diabetics (1.72 +/- 0.34 vs 2.00 +/- 0.44; p < 0.005) and they correlated with levels of glycosylated hemoglobin (p = 0.05; r = -0.266). CONCLUSION: despite similar level of other risk factors, EF was much more impaired in diabetic patients than in non-diabetics. These evidences further support the impact of DM on cardiovascular risk.

[Metabolic and cardiovascular effects of combined antiretroviral therapy in patients with HIV infection. Systematic review of literature]. / Effetti metabolici e cardiovascolari della terapia antiretrovirale combinata in pazienti con infezione da HIV. Rassegna sistematica della letteratura.

In HIV infected patients an increased incidence of cardiac events has been reported since the introduction of highly active antiretroviral therapy (HAART). Antiretroviral drugs' regimens are, in fact, associated with several metabolic side effects, such as dyslipidemia, impaired glucose metabolism and abnormal body fat distribution, that increase cardiovascular risk of HIV subjects. In addition, HIV infection itself, the chronic inflammatory status and the frequent presence in this population of traditional risk factors contribute to an higher incidence of cardio and cerebrovascular events. In last years several studies showed the occurrence of carotid vascular impairment in patients treated with protease inhibitors (PI). Similarly the DAD Study reported an increase of 26% of the risk of myocardial infarction in patients on HAART and that this risk was independently associated with longer exposure to PI, after multivariate adjustments. A correct evaluation of the metabolic status before starting HAART and an adequate control of drugs-related metabolic abnormalities may reduce the incidence of cardiac events and still improve HIV patients prognosis. This review will focus on the metabolic effects of antiretroviral drugs and on the contribution of combination antiretroviral therapy on cardiovascular risk.

[Clinical and therapeutic value of carotid intima-media thickness]. / Il valore clinico e terapeutico dello Spessore Medio-Intimale Carotideo.

Carotid Intima Media Thickness (IMT) has been widely used to predict cardiovascular events in primary and secondary prevention studies. Yet, the power of IMT to reclassify risk level on top of conventional risk assessment based on classical risk factors remains unsettled. In fact, recent data indicate that the prognostic power of IMT is lower than that provided by the identification of carotid plaques. The role of IMT as surrogate endpoint to assess the efficacy of cardiovascular protective therapies is also still debated. In fact, no studies have ever been designed and powered to show a relationship between changes in carotid IMT during follow-up and cardiovascular events. Recently, two meta-analysis of trials using IMT as surrogate endpoint failed to demonstrate an association between IMT regression and cardiovascular events. The reasons for the lack of predictive role for changes in IMT are uncertain. It has been shown that IMT is not a pure atherosclerotic index, being substantially affected by age and hemodynamic factors including blood pressure and vessel wall shear stress. In addition, the status of carotid vessels does not strictly reflect that of coronary arteries. Finally, intra and inter-observer variability of measurements may further limit the association between IMT changes in individual patients and cardiovascular risk. Thus, IMT represents a valuable risk marker in population studies but its role for tailoring cardiovascular therapy in clinical practice remains currently uncertain.

[From myocardium to the atherosclerotic plaque: new perspectives in cardiologic imaging]. / Dal miocardio alla placca aterosclerotica: le nuove prospettive dell'imaging in cardiologia.

Molecular imaging is an innovative and promising approach in cardiology for functional characterization of atherosclerosis. Nuclear, ultrasound and magnetic resonance imaging have been used for assessment of atherosclerosis of large and small arteries in several clinical and experimental studies. Positron Emission Tomography with fluorodeoxyglucose can measure metabolic activity and vulnerability of atherosclerotic plaques, identifying individuals at risk of future cardiovascular events. Magnetic resonance imaging can quantify carotid artery inflammation using iron oxide nanoparticles as contrast agent. In addition, macrophage accumulation of iron particles in atherosclerotic plaques may allow monitoring of inflammation during drug therapy, whereas contrast-enhanced ultrasound imaging may detect plaque neovascularization. Currently, technical factors, including cardiac and diaphragmatic motion and small size of coronary vessels, limit routine application of these techniques for coronary imaging. Purpose of this review is to describe state of the art and potential areas of clinical applications of molecular imaging of atherosclerosis.

Mapping and Ablation of Retrograde Conduction During a Nearly Incessant Pacemaker-mediated Tachycardia in a Patient with Third-degree Atrioventricular Block.

Patients with third-degree atrioventricular block implanted with a dual-chamber pacemaker in DDD mode can develop pacemaker-mediated tachycardias if retrograde ventriculoatrial (VA) conduction is present. Programming a long post-VA refractory period to avoid tachycardia initiation can be contraindicated if these patients have a good atrial response from exercise testing and require a high maximum tracking rate to allow for a proper response to sensed atrial rhythms. We report a case of a patient in whom mapping and ablation of retrograde conduction during the pacemaker-mediated rhythm was the only solution to allow both the programming of a high tracking rate and the elimination of tachycardia induction.

Ischemic heart disease in systemic inflammatory diseases. An appraisal.

Systemic inflammatory diseases are inflammatory syndromes that are associated with increased cardiovascular morbidity and mortality. The link between inflammatory and cardiovascular diseases can be attributed to coexistence of classical risk factors and of inflammatory mechanisms activated in systemic inflammatory diseases and involving the immune system. Yet, clinical implications of these findings are not entirely clear and deeper knowledge and awareness of cardiac involvement in inflammatory diseases are necessary. The aims of this review are to summarize cardiac involvement in systemic inflammatory diseases and to identify areas where evidence is currently lacking that deserve further investigation in the future.

Left ventricular hypertrophy reduction and clinical events. A meta-regression analysis of 14 studies in 12,809 hypertensive patients.

BACKGROUND: Left ventricular hypertrophy (LVH) is an independent risk factor for clinical events (CE), and regression of LVH is associated with reduction of cardiovascular risk. However, whether a continuous relationship between reduction of LVH and risk of CE exists has not been investigated. METHODS: Randomized clinical trials evaluating LVH at baseline and reporting quantitative LVH changes and CE, stroke or new onset heart failure) were included. Meta-regression analysis was performed to test the relationship between changes in LVH and incidence of the composite outcome (all-cause death, MI, stroke or new onset heart failure) and between changes of LVH and occurrence of each component of the composite outcome. Analysis of potential confounder variables was also performed. RESULTS: Fourteen trials including 12,809 participants and reporting 2259 events were included. Follow-up ranged from 0.50 to 5 years, with mean 1.97 ± 1.50 years. Mean age was 62 ± 5 years and 52% of patients were women. The composite outcome was significantly reduced by active treatments (OR: 0.851, IC: 0.780 to 0.929, p<0.001), as well stroke (OR: 0.756, IC: 0.638 to 0.895, p<0.001) whereas MI and new onset heart failure were not significantly reduced by treatments. LVH changes did not predict the reduction of CE. No significant influence on the association of baseline patients and studies characteristics was found. CONCLUSIONS: A significant continuous relationship between LVH changes and CE could not be demonstrated in hypertensive patients, independently on the technique or drug used. Ad hoc designed studies should further explore the relationship between LVH modification and outcomes in hypertensive patients.

[Cardiovascular risk in systemic inflammatory diseases]. / Il rischio cardiovascolare nelle patologie infiammatorie sistemiche.

Systemic inflammatory diseases are associated with increased cardiovascular morbidity and mortality. The link between inflammatory and cardiovascular diseases can be attributed to the coexistence of classical risk factors and inflammatory mechanisms activated during systemic inflammatory diseases involving the immune system. Unfavorable metabolic effects of anti-inflammatory drugs can also contribute to increase cardiovascular risk. Yet, clinical implications of these findings are not entirely clear, and deeper knowledge and awareness of cardiac involvement in inflammatory diseases are necessary. The aim of this review is to summarize cardiac involvement in systemic inflammatory diseases and to identify aspects where evidence is currently lacking that would deserve further investigation in the future.

Endothelial dysfunction in type 2 diabetic patients with normal coronary arteries: a digital reactive hyperemia study.

BACKGROUND: To assess endothelial function (EF) in type 2 diabetic patients with angiographically normal coronaries compared to diabetic patients with obstructive coronary artery disease (CAD) and to non-diabetic patients, with and without CAD. METHODS: One hundred eighty-three patients undergoing coronary angiography were divided in: group 1 with diabetes mellitus (DM) and CAD (n = 58); group 2 with DM without CAD (n = 58); group 3 with CAD without DM (n = 31) and group 4 without CAD and DM (n = 36). EF was assessed by reactive hyperemia index (RHI) using a fingertip peripheral arterial tonometry and compared to values obtained in 20 healthy volunteers. RESULTS: RHI was significantly lower in patients with DM compared to patients without DM (1.69 ± 0.38 vs 1.84 ± 0.44; p = 0.019). RHI was comparable among groups 1, 2 and 3, each value being significantly lower compared to group 4 (2 ± 0.44; p<0.001 vs group 1; p<0.005 vs group 2; p<0.002 vs group 3). At multivariate analysis DM and CAD were significant predictors of endothelial dysfunction (ED) (OR = 2.29; p = 0.012; OR = 2.76; p = 0.001, respectively), whereas diabetic patients (n = 116) CAD and glycated haemoglobin (HbA1c) were independent significant predictors of ED (OR = 3.05; p = 0.009; OR = 1.96; p = 0.004, respectively). Diabetic patients with ED (n = 67) had higher levels of HbA1c than diabetic patients with normal endothelial function (7.35 ± 0.97 vs 6.87 ± 0.90; p = 0.008) and RHI inversely correlated to HbA1c (p = 0.02; r = -0.210). CONCLUSIONS: Diabetic patients with and without CAD show significantly impaired peripheral vascular function compared to non-diabetic patients without CAD. ED in diabetic patients without CAD is comparable to that of patients with CAD but without DM. HbA1c is a weak independent predictor of ED.

Implantable cardioverter defibrillator to prevent sudden cardiac death in a patient with systemic sclerosis: A clinical case.

Ventricular arrhythmias are frequent in patients with systemic sclerosis and may result in sudden cardiac death. We report the case of a patient with systemic sclerosis and recent syncopes in whom induction of unstable sustained ventricular tachycardia of 2 different morphologies accompanied by syncopal event was demonstrated at the electrophysiological study. He was then implanted a 3rd generation implantable cardioverter defibrillator and remained thereafter asymptomatic. We suggest that aggressive testing is warranted in systemic sclerosis patients with suspected malignant arrhythmias to identify candidates for defibrillator implantation and prevent sudden deaths.

[Clinical applications of MIBG SPECT in chronic heart failure]. / Applicazioni cliniche della SPECT con MIBG nello scompenso cardiaco cronico.

Heart failure is characterized by several abnormalities of sympathetic cardiac activity that can be assessed by 123I metaiodobenzylguanidine single photon emission computed tomography (MIBG SPECT). This technique may be useful in the clinical management of heart failure patients. Abnormal MIBG uptake has been demonstrated to be a predictor of death and arrhythmic events in heart failure patients with a prognostic power incremental to that of conventional risk markers; it may also be useful to identify patients at low risk of arrhythmias despite current guideline indications for an implantable cardioverter-defibrillator (ICD) or patients at high risk for arrhythmias not fulfilling ICD indications. This review will focus on the clinical applications of MIBG SPECT in chronic heart failure, on the basis of the most recent evidence.

Assessment of cardiac sympathetic activity by MIBG imaging in patients with heart failure: a clinical appraisal.

Cardiac sympathetic activity can be assessed by (123)I-labelled meta-iodobenzylguanidine (MIBG) scintigraphy. Abnormalities of sympathetic cardiac activity have been shown in patients with heart failure, resulting in reduced MIBG uptake. Abnormal MIBG uptake predicts cardiac death, arrhythmias and all-cause mortality in patients with heart failure with a prognostic power incremental to that of conventional risk markers, and may identify patients at low risk of arrhythmias despite current guideline indications for implantable cardioverter defibrillator or patients at high risk for arrhythmias not fulfilling implantable cardioverter defibrillator indications. Prospective outcome studies are needed to assess whether MIBG imaging will have an impact on the mortality and morbidity of patients with heart failure.