Impact of insulin resistance on cardiac and vascular function.

BACKGROUND: Insulin resistance (IR), constitutes an important cardiovascular risk factor and can cause ischemic heart disease. It can lead to left ventricular dysfunction with a mechanism independent of ischemic heart disease and it is closely associated with impaired vascular function. The aim of our study was to explore the impact of IR on cardiac and vascular function, in patients with cardiovascular risk factors but angiographically undamaged coronary arteries. METHODS: We studied 32 patients (62.06±11.19years) with cardiovascular risk factors. All patients underwent coronary angiography, echocardiography, Doppler ultrasound of carotid arteries and laboratory tests. Exclusion criteria were coronary artery disease detected by coronary angiography, diabetes mellitus, creatinine above 1.5mg/dl, atrial fibrillation or malignant arrhythmias, left-ventricular hypertrophy, valvular heart disease, ejection fraction below 50%. The presence of insulin resistance was assessed using the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR). Each patient underwent a complete echocardiographic examination including Global Longitudinal Strain assessment and carotid artery ultrasound scan including measurement of arterial stiffness. RESULTS: The patients were divided into two groups based on the median value of HOMA-IR, the first group for values <4.14 and, the second, for values ≥4.14. Ejection fraction and diastolic function did not significantly differ between the two groups, whether in patients with higher levels of HOMA-IR (≥4.14) we observed a Global Longitudinal Strain (GLS) that was significantly reduced (-16.50±1.37% vs. -20.73±1.84%, p=0.0015) vascular stiffness, measured in the carotid arteries as pulse wave velocity (PWV) (9.70±1.75m/s vs. 7.40±1.89m/s, p=0.00148) that was increased. At multivariate analysis HOMA-IR was an independent predictor of myocardial dysfunction (GLS: coefficient 0.1156, p<0.0001). CONCLUSION: Insulin resistance is associated with subclinical myocardial and vascular alterations in patients without significant coronary artery disease, measured as a reduction of Global Longitudinal Strain, and increased arterial stiffness. Our results underscore the importance of studying the interaction between ventricular function and vessels, in the perspective of more effective preventive and therapeutic interventions.

Early detection of coronary artery flow and myocardial perfusion impairment in hypertensive patients evidenced by myocardial blush grade (MBG) and thrombolysis in myocardial infarction (TIMI) frame count (TFC).

OBJECTIVE: In hypertensive patients with typical chest pain but absence of coronary stenosis the coronary microcirculation may be impaired, thus, our study aimed to appraise, in these subjects, the role of the coronary microcirculation, assessed by Myocardial Blush Grade (MBG) and Thrombolysis in Myocardial Infarction (TIMI) Frame Count (TFC). METHODS: A total of 95 subjects with chest pain and uninjured coronary arteries were recruited into the study: 80 subjects were hypertensive while 15 subjects were normotensive. The hypertensive subjects were divided into two subgroups: hypertensive subjects with positive scintigraphy and hypertensive subjects with negative scintigraphy. The TFC, a quantitative method of assessing coronary artery flow, the MBG, an assessment of the level of tissue perfusion, and the Total Myocardial Blush Score (TMBS), the sum of the myocardial blush grades of each coronary territory, were evaluated on the coronary angiogram of every patient. RESULTS: The TFC was higher (p<0.05) in hypertensive subjects than in normotensive subjects. The MBG and the TMBS were lower (p<0.05) in hypertensive subjects than in normotensive subjects. The TFC was higher (p<0.05) in positive scintigraphy than in negative scintigraphy. The MBG was lower (p<0.05) in positive scintigraphy than in negative scintigraphy. The Spearman rank correlation test showed that the TFC and the MBG was inversely associated. CONCLUSION: The hypertensive subjects had impaired coronary artery flow and myocardial perfusion, documented by the TFC, MBG and myocardial perfusion scintigraphy. These methods may be universally applicable, in fact they are validated and most catheterization laboratories have access to them.

The role of macrophage colony-stimulating factor in patients with acute myocardial infarction: a pilot study.

We assessed whether macrophage colony-stimulating factor (M-CSF) levels are associated with left ventricular systolic dysfunction (LVSD) in patients with acute myocardial infarction (AMI). We studied 56 patients with AMI (mean age: 67 ± 12 years) and identified those with clinical (Killip class >II) or echocardiographic signs (ejection fraction ≤45%) of LVSD. We evaluated the established cardiovascular risk factors and measured several cardiovascular biomarkers, including M-CSF. Serum M-CSF concentrations (pg/mL) were significantly increased in patients with both clinical and echocardiographic signs of LVSD (460 ± 265 vs 290 ± 210, P = .0103 and 493 ± 299 vs 287 ± 174, P = .0028, respectively). We found a significant inverse association between M-CSF and ejection fraction (r = -.351, P = .0079). Logistic regression analysis revealed that, among all evaluated clinical and biochemical parameters, the stronger predictor of LVSD was M-CSF (odds ratios 2.1, 95% confidence interval 1.1-2.9, P = .0168). This is the first study reporting plasma M-CSF levels as independent determinants of low LV ejection fraction and clinical LV dysfunction in patients with AMI.

Chronic pharmacological treatment in takotsubo cardiomyopathy.

BACKGROUND: Takotsubo cardiomyopathy is a disorder that has been appreciated only recently. In most of reported cases, this syndrome mimes an acute myocardial infarction. Till this moment no data are available from literature about the treatment in the acute phase of this disease. AIM OF THE STUDY: In our multicentric experience we have retrospectively looked at the benefits of a treatment with ACE-inhibitors, beta-blockers, Aspirin and calcium channels blockers, started until the early phases of the disease and continued for 30 days, in 36 patients affected by Takotsubo cardiomyopathy. We chose as endpoint of the study the efficacy of the used drug in improving left ventricular myocardial function and the rapidity of the effects of the same drug.bethods: from an international registry about the Takotsubo cardiomiopathy, co-ordinate by our research group, we evaluated the long term efficacy of some drugs, administrated like single treatment in some patients. RESULTS: Obtained data did not show any statistically significant difference in the percentages of improvement in the left ventricle ejection fraction evaluated at the admission to the hospital, before the discharge and after 30 days of treatment between each treated group and the control group of non-treated patients. No significant differences were found in hospitalization times between treated patients and controls. None of our patients experienced during the observation period a relapse of the disease. CONCLUSIONS: The results of our survey suggest that a chronic treatment with beta-blockers, ACE-inhibitors, calcium channels blockers and aspirin does not provide any benefit in patients with Takotsubo cardiomyopathy. Thus, it seem to be important an early correct differential diagnosis to avoid any chronic treatment in these patients.

[Forty-slice multidetector computed tomography for non-invasive diagnostic approach to coronary artery disease]. / Approccio diagnostico non invasive con tomografia computerizzata multidetettore a 40 strati per lo studio della malattia aterosclerotica coronarica.

BACKGROUND: Multidetector computed tomography coronary angiography (MDCT-CA) is a non-invasive technique that clearly shows coronary anatomy and correctly identifies plaque location and morphology. In this study we assessed diagnostic accuracy of MDCT-CA in detectiong significant stenosis in patients with clinically relevant coronary tree disease. METHODS: . Fifty patients (38 males, 12 females, mean age 60.9 +/- 9.2 years) with atypical chest pain, stable or unstable angina pectoris, or non-ST-elevation myocardial infarction underwent MDCT-CA (Brilliance 40, Philips Medical Systems, Cleveland, OH, USA) within 3 days before diagnostic conventional coronary angiography. Inclusion criteria were sinus rhythm, heart rate <70 b/min, and ability to hold breath for more than 12 s. Exclusion criteria were known intolerance to contrast medium, serum creatinine >2 mg/dl, pregnancy, respiratory insufficiency, unstable clinical conditions, and severe heart failure. Beta-blockers were administered if heart rate was >70 b/min. To synchronize arrival of the contrast bolus (Iomeron 400, Bracco, Milan) in the coronary arteries with the start of the scan the bolus-tracking technique was used. Diagnostic accuracy was evaluated per segment, per vessel, and per patient. RESULTS: Mean heart rate during examination was 61.9 +/- 6.2 b/min; 618 segments were evaluated. The assessment was impaired by respiratory artifacts only in 1 patient (2%). MDCT-CA showed good sensitivity, specificity, and positive and negative predictive values in detecting significant coronary artery stenosis (94, 94, 91, and 96% per segment; 91, 97, 95, and 92% per vessel; 100, 100, 100, and 100% per-patient, respectively). CONCLUSIONS: Forty-slice MDCT-CA showed a good diagnostic capability in detecting significant coronary artery stenosis in patients referred to our institution for suspected or known significant coronary artery disease.