Comparison of coronary artery flow impairment in diabetic and hypertensive patients with stable microvascular angina

OBJECTIVE

Stable microvascular angina (SMVA) describes patients with angina, findings compatible with myocardial ischemia and normal coronary angiograms. The aim of this study was to evaluate the impact of diabetes on the coronary microcirculation troughs angiography indexes (TIMI Frame Count, Myocardial Blush Grade, Total Myocardial Blush Score) and a new index: Total TIMI Frame Count (TTFC).

PATIENTS AND METHODS

The study population included 310 patients with SMVA that we split into two populations: diabetic-non hypertensive (164 patients) and non-diabetic-hypertensive (146 patients). We calculated, on angiographic images of each patient, TIMI Frame Count (TFC), Myocardial Blush Grade (MBG) and Total Myocardial Blush Score (TMBS) using the protocol described by Gibson and Yusuf. On the basis of Yusuf's experience we imagined a new index: TTFC like sum of the three coronary TFC.

RESULTS

We found a worse coronary microcirculation in diabetic-non hypertensive patients with lower values of TFC, MBG and TMBS (p = 0.02), compared with non-diabetic hypertensive. New index TTFC is usually higher in diabetics-non hypertensive than non-diabetic hypertensive patients. Patients with positive scintigraphy had a worse TMBS than patients with a negative one, with a high statistical significance (p = 0.003).

CONCLUSIONS

Analysis of diabetic non hypertensive and non-diabetic and hypertensive patients with cardiac syndrome X has led to asses that the diabetic population has a greater involvement of microcirculation. Also the new index, TTFC, proved to be a good marker, in agreement with results of other indexes.

Short term prognostic role of NT-proBNP in patients after myocardial infarction

AIM

The clinical and prognostic role of cardiac natriuretic peptides (CNP) in patients with heart failure is well known; recently, several studies have evaluated the possibility of using CNP to evaluate their potential prognostic role in patients with acute coronary syndromes (ACS). The aim of this study was to evaluate the short term prognostic value of NT-proBNP in 70 patients admitted for ACS.

METHODS

The authors studied 70 patients with ACS, evaluating, at admission, clinical-anamnestic, instrumental and laboratory characteristics including NT-proBNP plasma levels. Patients were monitored in a 6-month-follow-up to record adverse fatal events and their possible correlation with baseline characteristics.

RESULTS

The incidence of adverse events during the follow-up period was 28% (10 patients). In patients with adverse events, the authors observed lower left ventricle ejection fraction (P=0.01), higher prevalence of ST elevation myocardial infarction (P=0.03) and higher NT-proBNP levels (P=0.03), compared to those without adverse events. Moreover, the logistic regression analysis underlined how ST elevation myocardial infarction (P=0.05) and higher NT-proBNP levels (P=0.05) were the only predictive variables for adverse events during the follow up period.

CONCLUSIONS

This study demonstrates the short term prognostic role of NT-pro BNP in patients admitted for ACS.

Prognostic role of endothelial dysfunction and carotid intima-media thickness in patients undergoing coronary stent implantation

AIM

Impaired endothelial function and increased carotid intima-media thickness are key events in the atherosclerotic process and predict future cardiovascular events in subjects with and without coronary artery disease. The purpose of this study was to investigate whether the vasodilator response to increased flow in the brachial artery and the presence of carotid lesions may have a prognostic significance for in-stent restenosis in patients undergoing coronary angioplasty.

METHODS

The study population included 58 patients undergoing percutaneous coronary intervention (PCI) with stenting and at least 10 months of follow-up. All patients underwent ultrasound detection of brachial artery reactivity 30 days after PCI. Flow mediated dilatation (FMD) was investigated after 5 minutes of occlusion of the artery and nitroglycerin mediated dilation (NMD) was investigated after administration of sublingual nitrates. Vascular echography was performed to measure intima media thickness (IMT) of carotid arteries. At baseline we evaluated all the established traditional cardiovascular risk factors. We also subdivided our study cohort according to values of FMD in patients with FMD above and patients below the median value.

RESULTS

Patients with FMD above the median value showed higher prevalence of hypertension (P=0.002), diabetes (P=0.02) and carotid IMT (P=0.006) than those below the median. Brachial FMD was inversely correlated (P=0.001) to carotid IMT. At the end of follow-up clinical events occurred in nine patients. In a multivariate analysis, including all the variables evaluated at baseline, carotid IMT (P=0.02), level of glycemia (P=0.001), a lower FMD (P=0.005) and presence of carotid plaque remained the only variables predictive of restenosis.

CONCLUSIONS

Evaluation of FMD and carotid IMT may provide important prognostic information in patients undergoing PCI.

Carotid and peripheral atherosclerosis in patients who underwent primary percutaneous coronary intervention and outcome associated with multifocal atherosclerosis

AIM

The aim of our study was to determine if patients with multifocal atherosclerosis have a worse prognosis than patients with atherosclerosis only in the coronary bed.

METHODS

We studied 45 subjects admitted to intensive coronary care unit of the Division of Cardiology with the diagnosis of acute myocardial infarction (AMI). Traditional cardiovascular risk factors were investigated and laboratory analysis included measurement of plasma lipids, glycemia, fibrinogen and high-sensitivity-C-reactive protein (hs-CRP). Each patient underwent coronary-angiography as well as carotid and peripheral arterial ultrasound examination. A follow-up of 13+/-2 months was performed.

RESULTS

We found that the severity of coronary atherosclerosis is significantly associated with the presence of carotid (P<0.05) and peripheral atherosclerosis (P<0.005). Markers of inflammation, hs-CRP (P<0.005) and fibrinogen (P<0.05), were significantly associated with multifocal atherosclerosis. We have shown that an increased number of coronary vessels with atherosclerotic stenosis is associated with a higher value of carotid (P<0.0001) and peripheral intima media thickness (P<0.0001). During 13 months of follow-up the incidence of fatal or non fatal events was 18%. The multivariate analysis showed that the variables independently associated with fatal and non fatal events were: male sex (P<0.001), family history of cardiovascular disease (P<0.005), hypertension (P<0.01), diabetes mellitus (P<0.05), higher levels of total cholesterol (P<0.05), smoking habit (P<0.05), and multifocal atherosclerosis (P<0.05).

CONCLUSIONS

The ultrasound examination of carotid and peripheral atherosclerotic lesions may be useful in placing patients with AMI in a category of higher risk of cerebrovascular and cardiovascular events. Moreover, the precocious identification of patients at risk can suggest a more aggressive pharmacological treatment and a more accurate follow-up in order to avoid future events.

Circulating endothelin-1 levels in type 2 diabetic patients with ischaemic heart disease

To investigate whether circulating endothelin-1 (Et-1) may be related to the increased incidence and severity of ischaemic heart disease in type 2 diabetes mellitus, we compared the concentrations in type 2 diabetic patients and in non-diabetic patients with coronary artery disease (CAD) angiographically documented. Plasma levels of Et-1 were determined in 34 type 2 diabetic patients with CAD (16 with stable angina, 6 with unstable angina, 12 with previous myocardial infarction) and in 19 nondiabetic patients with CAD (4 with stable angina, 5 with unstable angina, 10 with previous myocardial infarction). Fifteen diabetic patients without CAD and 9 healthy volunteers served as control subjects. In the type 2 diabetic patients, the mean Et-1 levels were 3.19 +/- 1.61 pmol/l in those with stable angina, 3.58 +/- 1.92 pmol/l in those with unstable angina, 4.24 +/- 2.53 pmol/l in those with myocardial infarction. These values were not significantly different one another, nor from the values obtained from type 2 diabetic controls (3.64 +/- 2.13 pmol/l). In the non-diabetic patients, the mean Et-1 levels were 3.92 +/- 0.73 pmol/l in those with stable angina, 4.35 +/- 1.67 pmol/l in those with unstable angina, 4.33 +/- 1.66 pmol/l in those with myocardial infarction. These values were not significantly different one another, but significantly higher than those obtained from healthy controls (2.07 +/- 0.67 pmol/l; P < 0.001). No significant differences were found in Et-1 levels between diabetic and non-diabetic patients with stable, unstable angina and previous myocardial infarction. In contrast, a statistically significant difference was found in Et-1 levels between diabetic and non-diabetic control subjects (P < 0.05). In conclusion, similar raised concentrations of Et-1 in diabetic and non-diabetic patients with stable, unstable angina and previous myocardial infarction do not support the hypothesis that higher levels of Et-1 in diabetic patients are responsible for the increased incidence of CAD in diabetes mellitus. However, the raised Et-1 levels found in diabetic patients in the absence of CAD strongly suggest that a generalised endothelial dysfunction, documented in our study by increased levels of Et-1, most probably precedes subsequent cardiovascular diseases.

[A new method for calculating the mass of the left ventricle by angiocardiography]

The authors describe a simplified method to determine left ventricular volume and mass from the ventricular silhouette, taken from a right oblique anterior angiographic projection at 30 degrees, used to measure the telediastolic surface and major axis, and of measuring the telediastolic thickness of the ventricular wall in the postero-lateral segment of the silhouette taken from a left oblique anterior angiographic projection at 60 degrees. Sixty-four ventricular silhouettes were analysed in patients undergoing left kineventriculography for coronaropathy and ventricular mass was determined using both the new and traditional methods. Using the new method mass values (mean value 87.85 g/sq.mt. and SD 34.04) were obtained which were significantly correlated (r = 0.999) with values obtained using the standard method (mean value 88.02 g/sq mt and SD 34.11). The practical advantages of the new method are discussed (simplicity of calculating equation without determining the minor axis of the ventricular silhouette), together with its limits due to the monoplanar technique used to calculate the volume and the measurement of wall thickness in those cases in which the postero-lateral wall is considered the most representative of the mean thicknesses of the left ventricular wall. Lastly, the paper discusses the possibility of applying this method to non-invasive procedures, such as the two dimensional echocardiogram, where more reliable mass values could be obtained even in the event of non-uniform wall thickness.