Bülent Özin

Effect of Mechanical Dyssynchrony and Cardiac Resynchronization Therapy on Left Ventricular Rotational Mechanics

Alterations in rotational mechanics can bring new aspects to the understanding of left ventricular (LV) dyssynchrony. The aims of this study were to investigate LV rotational mechanics in candidates for cardiac resynchronization therapy (CRT) and to assess the effect of CRT by speckle-tracking echocardiography. Fifty-four patients with heart failure and 33 healthy controls were studied. Thirty-three underwent CRT. Speckle tracking was applied to short- and long-axis views. Radial and longitudinal dyssynchrony were assessed as previously defined. Apical and basal rotations were measured as the average angular displacement about the LV central axis. LV twist and torsion were then calculated. Peak apical and basal rotation, peak LV twist and torsion, apical and basal rotation at aortic valve closure (AVC), and LV twist and torsion at AVC were significantly lower in patients than controls. Apical-basal rotation delay and AVC-to-peak LV twist interval were longer in patients and associated with decreased peak LV twist and LV twist at AVC, respectively. In patients, rotational indexes, particularly LV twist and torsion, were correlated strongly with radial dyssynchrony. LV torsion (cutoff 0.1 degrees /cm) and twist (cutoff 1 degrees ) at AVC had the highest sensitivity (90%) and specificity (77%) to predict CRT responders among all other parameters, including radial and longitudinal dyssynchrony. In conclusion, LV dyssynchrony is associated with discoordinate rotation of the apical and basal regions, which in turn significantly decreases peak LV twist and torsion and LV twist and torsion at AVC. CRT significantly restored the altered rotational mechanics in responders. These parameters have potential for predicting responders to CRT.

Prevention of contrast-induced impairment of renal function by short-term or long-term statin therapy in patients undergoing elective coronary angiography

A decline in kidney function after contrast exposure is associated with a high risk of morbidity and mortality during hospitalization and over long-term periods. Several retrospective and recent prospective clinical trials have shown that statin therapy might prevent contrast-induced nephropathy in patients undergoing percutaneous coronary intervention. In this study, we aimed to assess the effects of statin therapies on renal function parameters in patients undergoing elective coronary angiography. One hundred and sixty patients undergoing elective coronary angiography were randomized equally into two groups: atorvastatin 40 mg/day group (statin started 3 days before coronary angiography) and an untreated control group. An additional 80 patients were included as a chronic statin therapy group. Serum creatinine, serum cystatin C, and glomerular filtration rate (GFR) were measured before and 48 h after coronary angiography. Cockcroft–Gault and Modification of Diet in Renal Disease (MDRD) equations were used to determine GFR. After coronary angiography, serum creatinine and GFR determined by MDRD were significantly better in patients using atorvastatin than those in controls (P = 0.002 and P = 0.004, respectively). Postprocedure serum creatinine, cystatin C, and GFR determined by MDRD were also significantly better in chronic statin therapy group than those in controls (P = 0.006, P = 0.003, and P = 0.004, respectively). There were no differences in renal function parameters between the short-term atorvastatin group and the chronic statin therapy group. Our data demonstrate that the use of short-term atorvastatin and chronic statin therapy may have a role in protecting renal function after elective coronary angiography.

Value of Stress Myocardial Perfusion Scanning in Diagnosis of Severe Coronary Artery Disease in Liver Transplantation Candidates

BACKGROUND The significant potential for perioperative and late cardiovascular complications makes careful preoperative cardiac risk assessment imperative in liver transplantation candidates. OBJECTIVE To determine the sensitivity and specificity of myocardial perfusion scanning for detection of coronary artery disease (CAD) in liver transplantation candidates. PATIENTS AND METHODS We prospectively evaluated 93 liver transplantation candidates. Patients with known CAD were excluded. All patients, regardless of symptoms and risk factors, underwent myocardial perfusion scanning and coronary angiography. RESULTS Results of myocardial perfusion scanning were abnormal in 64 patients (68.8%) and normal in 29 patients (31.2%). Of patients with abnormal scans, only 6 (9.4%) had severe CAD at coronary angiography. None of the 29 patients with normal perfusion scans and the 24 patients with fixed defects had severe CAD; however, 6 of 40 patients (15.0%) with reversible perfusion defects had severe CAD at coronary angiography (P = .005). Alcoholic liver disease, reversible perfusion defects at myocardial perfusion scanning, left ventricular systolic dysfunction, and higher low-density lipoprotein (LDL) cholesterol and triglyceride levels were significantly associated with CAD. Defining reversible perfusion defects as a sign of ischemia, and fixed defects and normal perfusion as nonischemic, myocardial perfusion scanning had 100% sensitivity but 61% specificity for severe CAD. The tests accuracy was low (38%). CONCLUSIONS The results of reversible perfusion defects on myocardial perfusion scanning were sensitive but not specific for CAD in liver transplantation candidates. The high number of false-positive results decreased the tests accuracy.

Mean platelet volume is elevated during paroxysmal atrial fibrillation: a marker of increased platelet activation?

Paroxysmal atrial fibrillation might be a risk factor for stroke such as chronic atrial fibrillation. We examined the relation between mean platelet volume and paroxysmal atrial fibrillation to determine the effect of paroxysmal atrial fibrillation on the thrombotic state via elevated mean platelet volume. Mean platelet volume is a marker of platelet size, function, and activation. Increased mean platelet volume reflects active and large platelets that release more thromboxane A2 than smaller ones. We hypothesized that mean platelet volume is elevated in patients with paroxysmal atrial fibrillation. The study population comprised 103 consecutive patients who were detected to have paroxysmal atrial fibrillation by 24-h Holter monitoring and 87 control individuals with normal Holter monitoring. Mean platelet volume and inflammatory parameters were measured. Comprehensive clinical and echocardiographic data were collected. Patients with aortic and mitral stenosis, hyperthyroidism, hypothyroidism, malignancy, infection, and pregnancy were excluded from the study. Mean age of the patients was 63 ± 11 vs. 45 ± 14 years (P < 0.001) in paroxysmal atrial fibrillation and control groups, respectively. Fifty-seven patients (55%) in paroxysmal atrial fibrillation and 19 (21%) (P < 0.001) patients in control group were men. Mean platelet volume was significantly higher in the paroxysmal atrial fibrillation group when compared with control group (10.0 ± 2.0 vs. 8.3 ± 1.5 fl, respectively; P < 0.001). C-reactive protein (18.5 ± 28 vs. 3.8 ± 2 mg/l, respectively; P = 0.004) and erythrocyte sedimentation rate (21 ± 21 vs. 12 ± 7 mm/h, respectively; P = 0.01) were also higher in the paroxysmal atrial fibrillation group. There was no difference in white blood cell and platelet counts between groups. In a multivariate analysis, elevated mean platelet volume was associated with the occurrence of paroxysmal atrial fibrillation before and after adjustment for age and sex. Our results indicate that inflammatory markers such as C-reactive protein and erythrocyte sedimentation rate and the marker of platelet size and activity mean platelet volume are elevated in patients with paroxysmal atrial fibrillation.

Prevalence and Predictors of Arrhythmia in End Stage Renal Disease Patients on Hemodialysis

Background. Sudden death is common in end-stage renal disease (ESRD). Cardiac arrhythmia is observed frequently in patients with ESRD and is thought to be responsible for this high rate of sudden death. This study investigated the prevalence and the predictors of arrhythmia in patients on maintenance dialysis. Methods. Ninety-four patients on hemodialysis program were enrolled in the study. Routine laboratory results were noted. Arrhythmia, periods of silent ischemia, and heart-rate variability analyses were obtained from 24-hour Holter monitor recordings. Corrected QT (QTc) dispersion was calculated from 12-lead surface EKG. Echocardiographic and tissue Doppler examinations were performed on interdialytic days as well. Ventricular arrhythmia was classified according to Lown classification; classes 3 and above were accepted as complex ventricular arrhythmia (CVA). Results. The mean age was 52.5±13.2 years; 44 (46.8%) were women. Ventricular premature contractions were detected in 80 (85.1%) patients, of whom 35 (37.2%) were classified as complex ventricular arrhythmia (CVA). Coronary artery disease, hypertension, and QTc dispersion appeared as independent factors predictive of CVA development. Atrial premature contractions (APC) were detected in 53 patients (56.4%) and supraventricular arrhythmia in 15 (16%) patients; all were identified as atrial fibrillation. Duration of dialysis therapy was found as an independent predictor of APC. Conclusion. Arrhythmia is frequently observed in ESRD patients receiving hemodialysis and may be responsible for the high rate of sudden mortality. Hypertension, CAD, and QTc dispersion are independent predictors of CVA, and duration of dialysis therapy is an independent factor affecting APC development in these patients.

Association between postprandial hyperinsulinemia and coronary artery disease among non-diabetic women: a case control study

BACKGROUND We planned a case-control study to assess the relation of fasting glucose, fasting insulin, postprandial glucose and postprandial insulin levels with coronary artery disease in nondiabetic women. METHODS Among 968 consecutive nondiabetic women screened, 104 with coronary artery disease (mean age 60, 4+/-9) made up the study cohort (group I). One-hundred and four age-matched, nondiabetic women without coronary artery disease who had a similar lipid and blood pressure profile (group II), and 52 healthy, age-matched women served as controls (group III, real control group). Demographics, waist circumference, lipids, fasting glucose postprandial glucose, fasting and postprandial insulin levels were compared among the groups. A separate subgroup analysis were performed in patients with metabolic syndrome. RESULTS No differences were identified in terms of prevalences of risk factors between group I and group II. Women with coronary artery disease had higher postprandial insulin level than the women in group II and group III. In reverse stepwise logistic regression analysis postprandial hyperinsulinemia was found to be the single independent determinant for coronary artery disease for the entire study group as well as for women with metabolic syndrome. CONCLUSION Our data demonstrate that postprandial hyperinsulinemia is independently associated with coronary artery disease, irrespective of fasting glucose, postprandial glucose, and fasting insulin levels in nondiabetic women with clusterings of factors of metabolic syndrome.

Serum gamma-glutamyl transferase activity: new high-risk criteria in acute coronary syndrome patients?

In acute coronary syndromes (ACS), oxidation and inflammation have very important roles and in-vitro studies have demonstrated that &ggr;-glutamyl transferase (GGT) participates in such oxidative and inflammatory reactions. We aimed to evaluate the prognostic value of baseline serum GGT activity on the development of major adverse cardiac event (MACE) in the follow-up of the patients with ACS in coronary care unit (CCU), after 1 and 6 month periods. We included 117 patients (mean age: 61.2±11.3 years, 93 males) hospitalized in CCU with the diagnosis of ACS. All had baseline serum GGT activity and were free of systemic and hepatobiliary disease. MACE was defined as the composite of mortality from cardiac causes, recurrent hospitalization with ACS and nonfatal recurrent myocardial infarction diagnoses, to need for coronary revascularization during CCU, over 1 and 6 month follow-up periods. During the follow-up of CCU, MACE occurred in 17 (14.5%) patients (two died). Serum GGT activity was significantly higher in the patients with MACE than those free of MACE (P=0.001) and GGT was found as the independent predictor of the development of MACE-CCU [relative hazard: 1.05, 95% confidence interval (CI): 1.01–1.09, P=0.007]. During the follow-up of 1 month, MACE occurred in 23 (20.0%) patients (five died). Serum GGT activity was significantly higher in patients with MACE than those free of MACE (P=0.021) and GGT was found as the independent predictor of the development of MACE-1 month (relative hazard: 1.04, 95% CI: 1.01–1.08, P=0.039). During the follow-up of 6 months, MACE occurred in 24 (21.8%) patients (two died). Again, GGT was significantly higher in patients who developed MACE than those free of MACE (P=0.001) and GGT was found as the independent predictor of the development of MACE-6 months (relative hazard 1.06, 95% CI: 1.03–1.10, P<0.001). Serum GGT activity was found to be an independent predictor of the development of MACE in the patients with ACS during CCU, over 1 and 6 month follow-up periods.

The Effect of Dobutamine Stress on Left Ventricular Outflow Tract Gradients in Hypertensive Patients with Basal Septal Hypertrophy

Basal septal hypertrophy (BSH), a cause of left ventricular outflow tract (LVOT) obstruction, is thought to occur by increased ventricular dynamics. The aim of the study was to evaluate the effect of pharmacologic stress on LVOT gradients in a group of hypertensive patients with BSH. Dobutamine stress was used in 24 hypertensive patients (mean age 56 ±8 years; 11 women) with BSH and 20 normal controls (mean age 54 ±9 years; 7 women). Ejection fraction and myocardial mass, basal septal dimension, and LVOT diameter were measured with 2-dimensional echocardiography. LVOT velocities and transmitral velocities before and at peak dobutamine infusion were determined by continuous wave Doppler and pulsed Doppler, respectively. There were no differences in mean ejection fraction and myocardial mass between BSH patients (58 ±3%, 204 ±24 g) and normals (56 ±4%, 201 ±32 g). The basal septum was thicker in patients (1.55 ±0.2 cm) than in normals (1.03 ±0.1 cm, p<0.001). Maximum LVOT velocities were similar in BSH (1.2 ±0.4 m/sec) and normals (1.1 ±0.2 m/sec) at rest. At peak stress, maximum LVOT velocities were higher in BSH (3.3 ±0.6 m/sec) than normals (1.7 ±0.4 m/sec, p<0.001). LV rate-pressure product at peak stress was higher in BSH (23,326 ±4,388) than normals (17,592 ±2,409, p<0.001). LV isovolumetric relaxation time was prolonged, and the E/A ratio was decreased in the patients at rest (130 ±14 msec and 0.72 ±0.18, respectively, p<0.001). At peak stress, diastolic function did not significantly change in two groups. The correlations between LVOT velocity change by stress and mean LVOT diameter (r =-0.668, p<0.001) and mean BS thickness (r =0.610; p<0.001) were significant in the whole group. High velocities appeared on LVOT at peak pharmacologic stress in the hypertensive patients with BSH compared with control group. This suggests dynamic ventricular ejection by stress may contribute to hypertrophy of the basal segment, which is the closest part of septum to increased afterload.

Right Ventricular Function Is a Determinant of Long-Term Survival after Cardiac Resynchronization Therapy

BACKGROUND Right ventricular (RV) dysfunction is a marker of poor prognosis in patients with heart failure. The aim of this study was to investigate the impact of RV function on the long-term outcomes of patients undergoing cardiac resynchronization therapy (CRT). METHODS A total of 120 consecutive patients treated with CRT according to guideline criteria were followed over 5 years. Comprehensive echocardiographic analyses of RV function and radial and longitudinal mechanical left ventricular dyssynchrony were performed at baseline and 6 months after implantation. RV function was evaluated by two-dimensional longitudinal strain of the free wall, fractional area change, tricuspid annular plane systolic excursion, and tricuspid annular systolic velocity. Long-term follow-up events were defined as all-cause mortality, heart transplantation, or assist device implantation. RESULTS Long-term events occurred in 38 patients. Among the studied variables for RV function, RV strain < 18% had the highest sensitivity (79%) and specificity (84%) to predict a poor outcome after CRT (area under curve, 0.821; P < .0001). When adjusted for confounding baseline variables of ischemic etiology, mechanical dyssynchrony, left ventricular end-systolic volume, mitral regurgitation, and medical therapy, RV dysfunction remained independently associated with outcomes, indicating a 5.7-fold increased risk for hard events (P < .0001). CONCLUSIONS Preserved RV function as assessed by speckle-tracking strain imaging appears to be an independent predictor of long-term event-free survival after CRT.

Right ventricular contractile reserve in mitral stenosis: Implications on hemodynamic burden and clinical outcome

BACKGROUND We investigated whether isovolumic acceleration (IVA) under inotropic stimulation as a means of right ventricular (RV) contractile reserve, is a surrogate for hemodynamic burden and has prognostic value in patients with mitral stenosis (MS). METHODS Thirty-one pure MS patients and 20 controls underwent cardiac catheterization, exercise test, and dobutamine stress echocardiography. RV fractional area change (FAC), +dP/dt/P(max), RV tissue Doppler indices (isovolumic contraction [IVC] and systolic [S] velocity, and IVA) were measured. Patients were followed-up for the occurrence of cardiac adverse events. RESULTS Inotropic modulation unmasked statistically significant differences regarding magnitude of changes in IVA, IVC, S, and +dP/dt/P(max), but not RV FAC. Inability to increase IVA more than 6.5 m/s(2) was the only independent determinant of pulmonary capillary wedge pressure >or=18 mm Hg (P=.004). Although MS severity did not predict the RV contractile reserve and pulmonary artery pressure (PAP) behavior during inotropic stimulation, the RV contractile reserve was related to the degree of systolic PAP. IVA increases of <3.4 m/s(2) had 86% sensitivity and 75% specificity to predict unfavorable outcomes during long-term follow-up (20+/-8 months). CONCLUSION RV contractile reserve provides complementary data to the hemodynamic significance of MS severity, may contribute to clinical decision making, and be of prognostic value in these patients.