Role of mean platelet volume in triagging acute coronary syndromes.

BACKGROUND: Acute coronary syndromes, characterized by the rupture of unstable plaque and the subsequent thrombotic process involving platelets, have been increasing in relative frequency. The central role of platelet activation has long been noticed in this pathophysiology; hence, many therapies have been directed against it. In this study, we have aimed to search prospectively the value of mean platelet volume (MPV), which is a simple and accurate measure of the functional status of platelets, in patients hospitalized with diagnosis of acute coronary syndromes (ACS). MATERIALS AND METHODS: A total of 216 consecutive patients (156 male, 60 female) hospitalized with the diagnosis of non-ST segment elevation (NSTE) ACS within the first 24 h of their chest pain were enrolled. One hundred and twenty patients, matched according to sex and age, with stable coronary heart disease (CHD) (85 male, 35 female) were enrolled as a control group. Patients were classified into two group: those with unstable angina (USAP, n = 105) and those with non-ST segment elevation myocardial infarction (NSTEMI, n = 111). RESULTS: MPVs were 10.4 +/- 0.6 fL, 10 +/- 0.7 fL, 8.9 +/- 0.7 fL consecutively for NSTEMI, USAP and stable CHD with significant differences. Patients with ischemic attacks in the first day of hospitalization accompanied by >0.05 mV ST segment shift had significantly higher MPV compared to those without such attacks (P = 0.001). Multivariable logistic regression analysis yielded that MPV (P = 0.016), platelet count (P < 0.001), and the presence of >0.05 mV ST segment depression at admission (P = 0.002) were independent predictors of development of NSTEMI in patients presenting with NSTE ACS. CONCLUSION: In patients presenting with NSTE ACS, higher MPV, though there are overlaps among subgroups, indicates not only more risk of having NSTEMI but also ischemic complications.

Angiographic prevalence of myocardial bridging.

OBJECTIVE: Muscle fibers overlying the intramyocardial segment of an epicardial coronary artery are termed myocardial bridging. Variable prevalence has been described at autopsy and angiographic series with small and large sample sizes. The aim of the study was to investigate the angiographic prevalence of myocardial bridging in 25982 patients from Turkey. METHODS: We performed a retrospective study, evaluated the cases with myocardial bridging among patients undergone selective coronary angiography, and searched the angiographic prevalence of myocardial bridging in a very large sample size. We studied also the correlation between the severity of the bridging and risk factors for coronary artery disease. RESULTS: Among 25982 patients we found 316 cases of myocardial bridging in a retrospective manner. The total prevalence was 1.22%. Although, 96.52% of patients with myocardial bridging had the lesion in the left anterior descending coronary artery (LAD) as expected, distribution of bridges between mid- and distal segments were almost equal (52.79% and 47.21%, respectively). We subclassified patients in two groups, Group A (<50% of systolic compression) and Group B (>or=50% of systolic compression), according to the amount of systolic compression of LAD and studied relationship of risk factors for coronary artery disease between groups. Another subclassification was also made for patients having myocardial bridging without coronary or valvular heart disease and hypertrophic obstructive cardiomyopathy; Group 1 (<50% of systolic compression) and Group 2 (>or=50% of systolic compression). In these patients we studied correlation between the severity of the myocardial bridging and risk factors for coronary artery disease. The prevalence of bridges in circumflex and right coronary arteries individually and in all arteries as combination was also studied. CONCLUSION: In a very large group of patients from Turkey undergone selective coronary artery angiography, the angiographic prevalence of myocardial bridging was slightly higher than expected. Only diabetes mellitus as a risk factor for coronary artery disease was higher in groups representing <50% of systolic compression (Group A and 1) than in groups representing >or=50% of systolic compression (Group B and 2) but the importance of this result is not known.

Atrial natriuretic peptide predicts impaired atrial remodeling and occurrence of late postoperative atrial fibrillation after surgery for symptomatic aortic stenosis.

BACKGROUND: Aortic stenosis (AS) and atrial fibrillation (AF) are commonly encountered in clinical practice. Natriuretic peptides (NP) are endogenous cardiac hormones, which have been shown to increase in patients with heart failure, and valvular or congenital heart disease. We aimed to determine the association between atrial NP (ANP) and late postoperative AF after surgery for AS along with temporal changes in plasma ANP levels and left atrial (LA) volumes. METHODS: 22 patients (16 males/6 females, mean age: 61 years) with symptomatic AS and 8 healthy volunteers (5 males/3 females) were enrolled into our study. All the patients studied underwent transthoracic echocardiography, which was repeated during the follow-up. N-terminal ANP (N-ANP) was studied initially and at the 2-month follow-up. Postoperatively, the patients were followed up for 12 months for AF attacks. RESULTS: Patients with AS had significantly higher levels of N-ANP, left ventricular (LV) end-diastolic pressure, E/A ratio, LV mass and LA volumes compared to the controls. Patients with postoperative AF attacks were significantly older, had higher N-ANP levels and LV end-diastolic pressure in addition to higher LA volumes and longer symptom duration compared to patients without AF. Age at the time of operation (p = 0.011) and N-ANP at the 2nd month (p = 0.047) were found to be independent predictors for late AF attacks during follow-up in regression analysis. Besides, N-ANP (p < 0.001) at the 2-month follow-up independently predicted impaired LA remodeling. CONCLUSION: ANP might be an important factor to identify AS patients at risk for late postoperative AF attacks.

Mean platelet volume in the patients with cardiac syndrome X.

BACKGROUND: Angina with normal coronary arteries, cardiac syndrome X, is a diagnosis of exclusion. The exact mechanism of this clinical syndrome remains unclear. Although the prognosis is as good as equal to that of normal population, symptoms related with the syndrome impair largely quality of life. Mean platelet volume showing the platelet size is an indicator of platelet function. Larger platelets are more active than smaller ones. METHODS AND RESULTS: We designed a study, evaluated mean platelet volume of the patients with cardiac syndrome X (group A) and stable angina (group B) and investigated the relation between groups. Eighty patients with cardiac syndrome X with a mean age of 51.08 +/- 9.79 years and 67 patients with stable angina with a mean age of 55.16 +/- 11.96 years were studied. At the end of the study, mean platelet volume of group A was significantly higher than that of group B, 10.55 +/- 1.08 fl vs. 9.39 +/- 0.58 fl, respectively (P < 0.001). CONCLUSION: Raised platelet size has been shown to be associated with adverse cardiac events. Mean platelet volume has increased in acute coronary syndromes and also in cardiac syndrome X in our study. Life style modification may optimize platelet size and improve symptoms in these patients.

[Thrombotic, fibrinolytic and proliferative activities of pulmonary vascular bed in secondary pulmonary hypertension]. / Sekonder pulmoner hipertansiyonda pulmoner vasküler yatagin trombotik, fibrinolitik ve proliferatif aktiviteleri.

OBJECTIVE: To determine whether pulmonary vascular bed contributes to the development of in situ thrombosis and vascular remodelling in secondary pulmonary hypertension (SPH) via changes in its local secretory activities. METHODS: Seventy-one patients with the diagnosis of secondary pulmonary hypertension (38 females, mean age 40.36+/-1.05 years) were included in the study. Selective right and left heart catheterization was performed to each patient for diagnostic purposes. Blood samples obtained from left ventricle (LV) and pulmonary artery (PA) of each patient were analyzed for levels of plasminogen activator inhibitor-1 (PAI-1), platelet derived growth factor (PDGF), vascular endothelial growth factor (VEGF), D-dimer, von Willebrand factor (vWF), protein-C, antithrombin-III, fibrinogen, and plasminogen. Results were compared between LV and PA. Correlation analysis between each parameter and mean pulmonary artery pressure (MPAP) was performed. RESULTS: Although mean level of VEGF in LV and PA were found to be in normal range, it was significantly higher in LV than in PA (p<0.001). Mean PDGF and D-dimer levels, which remained in normal range were also higher in LV (p<0.001 and p<0.001, respectively) than in PA;.vWF showed similar degree of elevation in both LV and PA. Only one parameter, PAI-1, was found to be significantly higher in PA than in LV (p=0.012). Antithrombin-III, protein C, plasminogen, and fibrinogen levels showed no significant differences between two chambers. They also remained in normal range, except for fibrinogen, which was slightly elevated in both LV and PA. Correlation analysis revealed strong positive correlation between D-dimer level in both LV and PA and MPAP (r=0.775, p<0.001 and r=0.649, p<0.001, respectively). CONCLUSION: In SPH, pulmonary vascular bed shows increased thrombotic, hypofibrinolytic, and proliferative activities, which are partially related to the severity of illness.

Sympathetic overactivity in patients with rheumatic mitral stenosis.

BACKGROUND: Mitral stenosis may increase sympathetic nervous activity by increasing left atrial pressure and reducing cardiac output. And elevated sympathetic nerve activity may be a risk factor for the development of clinical manifestations of mitral stenosis. In this study, we assessed the autonomic nervous system activity in patients with mitral stenosis by heart rate variability analysis and defined factors affecting autonomic functions. METHODS AND RESULTS: Fifty-four patients with rheumatic mitral stenosis were compared with an age- and gender-matched control group composed of 42 healthy individuals. SDNN, RMSSD, PNN50, and HF were lower; mean heart rate (HR), LF and LF/HF ratio were higher in the patients with mitral stenosis compared to the control group. SDNN was correlated positively with left ventricle ejection fraction (LVEF), negatively with mitral valve area, left atrial (LA) diameter, and duration of symptoms. RMSSD was correlated positively with mean transmitral gradient, negatively correlated with age; PNN50 was correlated negatively with mitral valve area and positively correlated with transmitral gradient. LF was positively and HF was negatively correlated with LA diameter; LF was correlated positively, and HF was negatively correlated with duration of symptoms. LF/HF ratio was positively correlated with LA diameter and duration of symptoms, negatively with LVEF and mean valve area. CONCLUSION: As a result, sympathetic nervous system activity is increased in patients with mitral stenosis and sympathetic overactivity worsens their symptoms. Most significant factors that affect autonomic functions in these patients are left atrial dilatation and mitral valve area.

Lipid profile of patients with aortic stenosis might be predictive of rate of progression.

BACKGROUND: Aortic stenosis is one of the most commonly encountered valvular pathology requiring surgery in developed countries. There are similarities between risk factors for coronary atherosclerosis and the development of aortic stenosis. We designed a retrospective study, evaluated the lipid profile and previous echocardiographic recordings of patients with aortic stenosis, and searched the association of rate of progression and lipid profile. METHODS AND RESULTS: The annual rates of progression in the peak and mean aortic gradients were 8.5 +/- 3.2 and 6.7 +/- 2.2 mm Hg/year, respectively. We classified the annual rate of progression of peak aortic gradient into 2 groups, group 1 with <10 mm Hg ("slow progressors") and group 2 with > or =10 mm Hg annual rate of progression ("fast progressors"). The annual rate of progression in group 1 was significantly higher than that in group 2, both in peak and mean aortic gradients (12 +/- 2 mm Hg and 6.4 +/- 1.6 mm Hg; 9 +/- 1.3 mm Hg and 5.2 +/- 1.1 mmHg; P <.001 for both). There was a highly significant difference between group 1 and group 2 for total cholesterol/high-density lipoprotein (HDL) cholesterol level ratio (7.1 +/- 1.4 vs 5.2 +/- 1.3, P <.001). There was a significant correlation between annual rate of progression in peak gradient and total cholesterol/HDL cholesterol level ratio (r = 0.399, P =.009). Smoking (P =.024, Beta = 0.26), presence of coronary heart disease (P =.011, Beta = 0.31), and total cholesterol/HDL cholesterol level ratio (P =.004, Beta = 1.98) were independently predictive of fast progression of the peak aortic gradient in the regression analysis. CONCLUSION: In a small group of patients from Turkey with aortic stenosis, there seems to be an association between the rate of progression and total cholesterol/HDL cholesterol level ratio, with fast progression occurring in the group with higher ratios.

Association between mean platelet volume and autonomic nervous system functions: Increased mean platelet volume reflects sympathetic overactivity.

BACKGROUND: Increased mean platelet volume (MPV) may reflect increased platelet activation or increased numbers of large, hyperaggregable platelets, and is accepted as an independent coronary risk factor. The adrenergic system has effects on platelet activation and thrombocytopoiesis. OBJECTIVE: To assess the effects of autonomic nervous system activity on MPV in patients with acute myocardial infarction (MI). METHODS AND RESULTS: Forty-seven patients with acute anterior MI were compared with 32 patients with healthy coronary arteries. All patients underwent heart rate (HR) variability analysis using 24 h Holter monitoring. Blood samples were taken for MPV measurements twice a day (day- and nighttime) during Holter monitoring. Mean HR, low frequency band of HR variability power spectrum to high frequency band of HR variability power spectrum (LF:HF) ratio, LF and MPV were higher in patients with anterior MI than in the control group. SD of all NN (RR) intervals, root mean square of successive differences, number of NN intervals that differed by more than 50 ms from the adjacent interval divided by the total number of all NN intervals, HF bands and platelet counts were lower in the patients with anterior MI than in the control group. Daytime LF bands, LF:HF ratio and MPV were significantly higher, and HF bands were significantly lower than the nighttime values for both groups. The differences in daytime and nighttime measurements were more significant in the patients with acute MI than in the control group. Pearson's correlation analysis showed that MPV was positively correlated with ventricle score, degree of left anterior descending artery stenosis, mean HR, LF bands and LF:HF ratio; and negatively correlated with the SD of all NN intervals, HF bands and platelet count. Multivariate analysis revealed that MPV was significantly affected by ventricle score and the LF:HF ratio. CONCLUSIONS: MPV was significantly higher in the patients with acute MI. In both groups, MPV showed great daytime and nighttime variation, which can be attributed to alterations in the autonomic nervous system. The authors suggest that the prognostic role of increased MPV in patients with acute MI is closely associated with increased sympathetic activity and decreased HR variability.