Pulsed-wave tissue Doppler quantification of systolic and diastolic function of viable and nonviable myocardium in patients with ischemic cardiomyopathy

Background

Detection of myocardial viability is crucial for clinical treatment of patients with ischemic cardiomyopathy. Currently, quantitative information for the evaluation of systolic and diastolic function of viable tissue is limited. Our aim was to compare quantitatively systolic and diastolic function in viable and nonviable dysfunctional myocardium in patients with ischemic cardiomyopathy.

Methods

A total of 93 patients (mean age, 62 ± 10 years) underwent dobutamine stress echocardiography to assess myocardial viability. Pulsed-wave tissue Doppler imaging (TDI) was used to assess systolic ejection velocity (V_S) and early (V_E) and late (V_A) diastolic velocities at rest and at low-dose dobutamine infusion (10 μg/kg per minute) in viable and nonviable dysfunctional regions. Analysis was repeated after dividing study population in patients ≥65 years old (n = 40) and <65 years old (n = 53).

Results

Pulsed-wave TDI demonstrated that V_S was comparable in dysfunctional viable and nonviable regions at rest (V_S, 6.3 ± 1.9 cm/s vs 6.3 ± 2.0 cm/s, respectively, P = .93). However, at low-dose dobutamine challenge, V_S was significantly higher in viable regions (8.5 ± 2.7 cm/s vs 7.8 ± 2.4 cm/s, P = .002). Viable regions had higher V_E at rest compared with nonviable regions (8.4 ± 2.5 cm/s vs 7.5 ± 2.8 cm/s, P = .003). Myocardial velocities were significantly higher in patients ≥65 years old, both in viable and nonviable regions.

Conclusions

Quantification of myocardial motion by pulsed-wave TDI demonstrates that at low-dose dobutamine stress, systolic velocity is markedly improved in viable myocardium, indicating the presence of contractile reserve in viable regions. A superior early diastolic filling at rest can also differentiate viable from nonviable myocardium.     

Effects of multivitamins and low-dose folic acid supplements on flow-mediated vasodilation and plasma homocysteine levels in older adults

Background

Hyperhomocysteinemia is associated with aging, endothelial dysfunction, and increased risk of coronary heart disease in older adults; however, the effects of homocysteine-lowering therapy on vascular reactivity in older persons are unknown. The objective of this study was to determine the effects of multivitamins (MV) and folic acid (FA) supplements on flow-mediated vasodilation (FMD) in older adults.

Methods

Individuals ≥70 years old with homocysteine levels ≥10 μmol/L were recruited for this 40-week, prospective, single-blinded study. All subjects were treated sequentially, with each of the following daily therapies for 10 weeks: (1) placebo, (2) MV (400 μg FA, 6 mg vitamin B₆, 25 μg vitamin B₁₂), (3) placebo, then (4) MV + FA (total FA, 1400 μg). FMD, folate intake, and laboratory values were measured at each visit. Investigators were blinded to subject treatment phase when measuring vessel diameters and calculating FMD.

Results

Twenty subjects (mean ± SEM age, 78.0 ± 1.2 [range, 70 to 88] years, 9 women) completed the MV and 17 completed the MV + FA interventions. FMD was impaired at baseline (2.0% ± 1.2%). During the 40-week study, homocysteine levels decreased by 1.4 ± 0.9 μmol/L (p_trend = 0.034) from a baseline of 12.8 ± 0.6 μmol/L; however, FMD did not change significantly (p_trend = 0.874). FMD did not improve after therapy with MV alone (3.0% ± 0.9% [week 10] vs 2.4% ± 1.1% [week 20], P = .716) or with MV + FA (2.6% ± 0.9% [week 30] vs 1.9% ± 0.7% [week 40], P = .484).

Conclusions

At doses commonly prescribed in clinical practice, MV and FA supplements did not improve FMD in older adults with hyperhomocysteinemia.     

Comparison of the effect of valsartan and lisinopril on autonomic nervous system activity in chronic heart failure

Background

In chronic heart failure (CHF), the derangement of autonomic nervous system activity has a deep impact on the progression of the disease. It has been demonstrated that modulation of the renin-angiotensin aldosterone system (RAAS) increases autonomic control of heart rate and reduces adrenergic activity. We sought to evaluate, in CHF, the different effects of an ACE inhibitor (lisinopril) and of an AT1 receptor antagonist (valsartan) on heart rate variability, baroreflex sensitivity and norepinephrine plasma levels.

Methods

Ninety patients (61 ± 10 years, 2.3 ± 0.5, New York Heart Association class) with CHF and left ventricular ejection fraction <40% were randomly assigned in a double-blind fashion to receive lisinopril (uptitrated to 20 mg/d) or valsartan (uptitrated to 160 mg/d) therapy for 16 weeks. Heart rate variability (evaluated by measuring standard deviation of normal R-R intervals on 24-hour ECG recordings), spontaneous baroreflex sensitivity and aldosterone and norepinephrine plasma levels were assessed before and after drug therapy.

Results

There were no significant differences between valsartan and lisinopril in their effects on left ventricular function, arterial pressure, aldosterone plasma levels and autonomic control of heart rate. Both lisinopril and valsartan significantly reduced plasma norepinephrine levels, but the reduction induced by valsartan was significantly greater than that observed for lisinopril (27% vs 6%, P < .05).

Conclusions

This study shows a comparable effect of ACE inhibition (lisinopril) and of AT1 receptor antagonism (valsartan) on cardiac vagal control of heart rate, whereas valsartan has shown a more effective modulation of sympathetic activity measured by plasma norepinephrine levels.     

Impact of physical training and detraining on endothelium-dependent vasodilation in patients with recent acute myocardial infarction

Background

There is evidence that aerobic exercise improves endothelial function in healthy subjects as well as in patients with chronic heart failure. However, it is unknown whether this effect occurs in patients with recent myocardial infarction (AMI).

Methods

Fifty-two patients with a recent first uncomplicated AMI underwent endothelial function evaluation before and after 3 months of moderate aerobic exercise training. We measured brachial artery vasomotor reactivity using flow-mediated dilation (FMD), a cold pressor (CP) test, and sublingual nitroglycerin. Patients were randomized into 2 groups: 28 patients (G1) underwent training, while 24 patients (G2) served as controls. Brachial artery vasomotor reactivity was reassessed after 1 month of detraining (DT).

Results

At baseline the FMD was 1.66% ± 4.11% in G1 and 2.04% ± 3.4% in G2 (P = NS) and vasoconstriction was evident after a CP test. The diameter reduction was −4.1% ± 3.89% in G1 and −4.39% ± 5.67% in G2 (P = NS). At follow-up the FMD had increased to 9.39% ± 4.87% in G1 (P < .01) and to 4.4% ± 3.9% in G2 (P < .01 vs G1). Vasoconstriction during a CP test was observed only in G2. Endothelium-independent vasodilation was unchanged in both groups. Effort tolerance increased by 32% in G1 patients (P < .01 versus G2) and was correlated with FMD change (R = 0.51, P < .01). After detraining the FMD was significantly reduced in G1 (P < .01) and a further vasoconstriction was evident after CP testing.

Conclusions

Exercise training improves endothelium-dependent vasodilation in post-AMI patients. This improvement is associated with a significant increase in exercise tolerance. These benefits disappeared after detraining.     

Hemodynamic response of a canine model of chronic heart failure to intravenous dobutamine,nitroprusside, enalaprilat,and digoxin

Summary The hemodynamic effects of acute intravenous administration of nitroprusside, dobutamine, enalaprilat, and digoxin was investigated in a canine model of chronic heart failure (CHF) produced by multiple sequential intracoronary microembolizations. Dobutamine (4 µg/kg/min) increased cardiac output (2.4±0.1 vs. 4.0±0.4 l/min; p<.001) and LV ejection fraction (LVEF; 26±1 vs. 30±4%; p<.01), and decreased systemic vascular resistance (SVR; 3620±170 vs. 2470±190 dynes sec cm^–5; p<.001). Nitroprusside (3 µg/kg/min) acted as a venodilator; it decreased pulmonary artery wedge pressure (16±1 vs. 13±1 mmHg; p<.01) and SVR (3730±440 vs. 3210±280 dynes sec cm^–5; NS) but had no effect on cardiac output. Enalaprilat (1.875 mg) produced a significant increase of cardiac output (3.0±0.5 vs. 3.8±0.5 l/min; p<.001) and LVEF (22±1 vs. 30±1%; p<.01), and decreased SVR (3280±400 vs. 2450±250 dynes sec cm^–5; p<.01). Intravenous digoxin at a cumulative dose of 0.75 mg increased LVEF (23±2 vs. 31±2%; p<.01) but had no effect on SVR. These data indicate that this canine model of CHF responds to acute pharmacologic intervention in a manner comparable to that seen in patients with CHF. Accordingly, this model may be a useful tool for the preclinical evaluation of new drugs targeted toward the treatment of CHF and for investigating the mechanisms of action of drugs currently used for the treatment of this disease state.     

Effect of nesiritide (human b-type natriuretic peptide) and dobutamine on heart rate variability in decompensated heart failure

Background

Previous studies have suggested that natriuretic peptides may have direct sympathoinhibitory effects. Nesiritide (recombinant human B-type natriuretic peptide) has been recently approved for treatment of decompensated congestive heart failure (CHF). We sought to assess the effects of nesiritide compared with dobutamine on time-domain indices of heart rate variability (HRV) in patients with decompensated CHF.

Methods

The study population consisted of 185 patients, who were randomized to intravenous nesiritide at a low (0.015 μg/kg/min, n = 56) or high (0.03 μg/kg/min, n = 58) dose, or to dobutamine (≥ 5 μg/kg/min, n = 58). Time-domain HRV indices were obtained from 24-hour Holter recordings immediately before and during study drug therapy.

Results

Dobutamine therapy resulted in a decrease in standard deviation of the R-R intervals over a 24-hour period (SDNN), standard deviation of all 5-minute mean R-R intervals (SDANN), and the percentage of R-R intervals with >50 ms variation (pNN50) (all P < .05). Low-dose nesiritide induced an increase in SDNN (P < .05), and high-dose nesiritide resulted in a nonsignificant decrease in all measures of HRV. A significant interaction was noted between baseline HRV and the effect of vasoactive therapy on HRV (P = .028). Therefore, the effect of nesiritide and dobutamine was analyzed in relation to baseline HRV. In the dobutamine group, patients with moderately depressed HRV at baseline displayed a reduction in SDNN (P = .01), SDANN (P = .01), pNN50 (P = .04), and the square root of mean squared differences of successive R-R intervals (RMSSD) (P = .05), whereas no significant changes occurred in patients with severely depressed HRV. In the low-dose nesiritide group, patients with severely depressed HRV displayed an increase in SDNN (P = .001), SDANN (P = .02), and RMSSD (P = .01), with no significant changes in patients with moderately depressed HRV. HRV response to high-dose nesiritide was similar to that of dobutamine.

Conclusions

Low-dose nesiritide therapy in patients with decompensated CHF improves indices of overall HRV and parasympathetic modulation, particularly if HRV is severely depressed at baseline. Dobutamine and possibly high-dose nesiritide can potentially lead to further deterioration of autonomic dysregulation.     

CardioSEAL/STARflex versus Amplatzer devices for percutaneous closure of small to moderate (up to 18 mm) atrial septal defects

Background

The Amplatzer septal occluder (ASO) allows the percutaneous closure of small to very large atrial septal defects (ASDs). The CardioSEAL/STARflex (CS/SF) can be used only for closure of small to moderate ASDs (stretch size up to 18 mm). These 2 devices are widely used in clinical practice. Therefore, a comparison of their use in the closure of small to moderate ASDs is needed.

Methods

From December 1996 to September 2002, 274 consecutive patients (mean age 20.3 ± 17 years) underwent percutaneous closure of small to moderate ostium secundum ASDs. The CS/SF device was used in 121 patients, and the ASO was used in 153.

Results

There were no differences in age, sex ratio, or pulmonary/systemic flow ratio. Stretch size of the defect was higher in the ASO group (13.6 ± 3.5 mm vs 15.5 ± 3.2 mm, P < .001). Procedure time and fluoroscopy time were shorter in patients treated with the ASO (61 ± 21 vs 75 ± 32 min, P < .0003, and 11.6 ± 9 vs 23.8 ± 17.4 min, P < .0001, respectively). Residual shunt at procedure and discharge was significantly more frequent in the CS/SF group (P < .0001). There were no differences in the complication rate for the 2 groups (CS/SF 4/121 vs ASO 6/153). Length of follow-up was longer in the CS/SF group (24 ± 14 vs 16 ± 9 months, P = .0001). Residual shunting was significantly more frequent in the CS/SF group during follow-up, while closure rate reached 100% after 1 month in ASO group.

Conclusions

The 2 devices are clinically safe and effective in ASD closure. However, percutaneous closure of small to moderate ASDs with ASO is quicker and provides an higher rate of complete occlusion.     

Effect of dietary intervention and lipid-lowering treatment on brachial vasoreactivity in patients with ischemic heart disease and hypercholesterolemia

Background

The “Mediterranean” diet and statin treatment have both independently been shown to improve survival and reduce the risk of cardiovascular events in patients with ischemic heart disease (IHD), but no studies have evaluated the effect of this combination on endothelial function. We therefore sought to evaluate the effect of the combination dietary intervention and lipid-lowering treatment on brachial vasoreactivity.

Methods

A total of 131 consecutive patients with documented IHD and a serum cholesterol level ≥5 mmol/L (193 mg/dL) were randomized to receive Mediterranean dietary advice (n = 68) or no specific dietary advice (n = 63). Endothelial function was assessed at baseline and after 12 months with noninvasive ultrasound scanning vessel-wall tracking of brachial artery flow-mediated vasodilatation (FMD). All patients started statin treatment with Fluvastatin (40 mg once daily) at baseline.

Results

A total of 115 patients completed the study. At baseline, FMD was 4.30% ± 4.89% in the control group versus 4.32% ± 6.15% in the intervention group (P = not significant). After 12 months of follow-up, FMD was significantly higher in the intervention group (control group 5.72% ± 4.87% vs intervention group 8.62% ± 6.60%, P < .01). This was accompanied by a larger intake of fatty fish and a significant decrease in triglyceride levels. In multivariate analysis, randomization status was a significant predictor of FMD after adjustment for classic cardiovascular risk factors and vessel size (P = .02; β = −2.66 [−4.91; −0.41]).

Conclusion

Dietary intervention with the Mediterranean diet and statin treatment improve FMD in the brachial artery in patients with IHD and hypercholesterolemia to a greater degree than statin treatment alone.     

Echocardiographic predictors of exercise capacity in patients with heart failure and systolic dysfunction: role of mitral regurgitation

Introduction and objectives

Patients with heart failure and similar left ventricular systolic dysfunction have differing exercise capacity. The aim of this study was to identify echocardiographic predictors of exercise capacity in patients with heart failure and systolic dysfunction.

Methods

We included 150 patients with class II (70%) or III (30%) heart failure with left ventricular ejection fraction below 40%. Six-minute walking test and cardiac color Doppler-echo, including tissue Doppler of mitral and tricuspid rings, were performed. Moderate and severe mitral regurgitation were considered as significant. Two groups were divided according to the median walking distance (290 m): Group 1, <290 m and Group 2, ≥290 m.

Results

Mitral regurgitation was detected in 112 patients (75%), which was significant in 40 (27%). Group 1 showed more significant mitral regurgitation (35 vs 18%), increased left atrium area (27±1 vs 24±1 cm²), mitral E amplitude (88±5 vs 72±3 cm/s) and systolic pulmonary pressure (37±1 vs 32±1 mmHg, all P<.05). By logistic regression analysis, only the presence of significant mitral regurgitation was independently associated with less walked distance (odds ratio: 3.44 95% confidence interval 1.02-11.66, P<.05). By multiple linear regression, the only independent predictor of walked distance was left atrium area (r=0.25, beta coefficient: −6.52 ± 2, P<.01).

Conclusions

In patients with class II-III heart failure and left ventricular systolic dysfunction, the main echocardiographic predictors of exercise capacity are related to the presence of significant mitral regurgitation.Full English text available from:www.revespcardiol.org     

Tamoxifen improves endothelial function and reduces carotid intima-media thickness in postmenopausal women

Background

Tamoxifen is a selective estrogen-receptor modulator shown to improve several cardiovascular risk factors in postmenopausal women with breast cancer. In animal studies tamoxifen inhibits the progression of atherosclerosis. Although the presence of a history with tamoxifen treatment is related to a lower intima-media thickness (IMT) of the common carotid artery, data from controlled follow-up studies are lacking to support this observation.

Methods

We examined 14 postmenopausal women with early stage breast cancer with indication for tamoxifen treatment (20 mg/d) and 13 healthy postmenopausal women. Flow-mediated dilatation (FMD) of the brachial artery, combined carotid IMT, and aortic pulse wave were measured before and 6 months after treatment in the tamoxifen group and at the same times in the control group.

Results

FMD and IMT were significantly increased and decreased, respectively, in the treatment group compared to the control group (FMD: +2.2% ± 0.9% vs +0.085% ± 1%, P = .012; IMT: −0.088 ± 0.03 mm vs +0.04 ± 0.03 mm, P = .018, mean ± standard error of the mean, treatment vs control group). These differences remained significant even when adjusted for age, duration of menopause, and cardiovascular risk factors. Low-density lipoprotein cholesterol was also significantly reduced after tamoxifen treatment.

Conclusions

Tamoxifen treatment slows the progression of atherosclerosis in postmenopausal women with breast cancer as assessed by changes in carotid IMT. An improvement in endothelial function and blood lipid profile may be the reason for this beneficial effect.     

Physiologic evaluation of myocardial bridging: a new analysis for an old disease

Background

Myocardial bridging (MB) is the most common congenital coronary anomaly. However, the functional relevance of MB is not well understood.

Methods

Eighteen patients with lone MB were consecutively enrolled. Fractional flow reserve (FFR) was measured before and after dobutamine infusion. Diastolic FFR was calculated by offline analysis. Cutoff values for functional significance of FFR and diastolic FFR were 0.75 and 0.76, respectively.

Results

Baseline systolic percent diameter stenosis and lesion length of MB were 70 ± 16% and 24 ± 7 mm. FFR and diastolic FFR were 0.92 ± 0.05 and 0.89 ± 0.07 at maximal hyperemia induced by adenosine, respectively (P = 0.006). Despite the angiographic stenosis, only 1 lesion was functionally significant. After dobutamine infusion, percent diameter stenosis (84 ± 11%, P = 0.002) and lesion length (26 ± 6 mm, P = 0.019) were aggravated and diastolic FFR was lowered (0.84 ± 0.10, P = 0.006). Two additional lesions became functionally significant after dobutamine infusion. Angiographic percent diameter stenosis at diastole was correlated with dobutamine diastolic FFR (R = -0.58, P = 0.04), but stenosis at systole was not. During median follow-up of 54 months, 2 patients underwent target-lesion revascularization.

Conclusions

Dobutamine increased the morphologic and functional severity of MB. Dobutamine-FFR seems to be helpful in the functional assessment of MB.     

Acute effects of β-endorphin on cardiovascular function in patients with mild to moderate chronic heart failure

Background

Cardiomyocytes produce opioid peptides and receptors. β-Endorphin is increased in the plasma of patients with congestive heart failure (CHF). We evaluated whether an intravenous infusion of β-endorphin exerted any effect on cardiovascular function and on the neurohormonal milieu in patients with mild to moderate CHF.

Methods

According to a double-blind, placebo-controlled design, 10 patients (5 men, age 46.9 ± 8.2 years [mean ± SD]) with CHF and New York Heart Association functional class II to III received, in random order, 1-hour intravenous infusion of β-endorphin (500 μg/h) and, on a separate occasion, received placebo and underwent echocardiographic and laboratory measurements at baseline and during infusions.

Results

β-Endorphin significantly increased left ventricular ejection fraction (LVEF) (P = .0001) and stroke volume (P = .0001), and reduced systemic vascular resistance (P = .031) in patients with CHF. These changes were paralleled by a significant increase in plasma levels of glucagon (P = .0001), GH (P = .0001), and IGF-1 (P = .0001), and a significant decrease in plasma levels of endothelin (P = .0001) and catecholamines (P = .01). No hemodynamic and neurohormonal changes were observed during the placebo study in any patient.

Conclusions

We conclude that a short-term, high dose infusion of β-endorphin improves LVEF, reduces systemic vascular resistance, blunts the neurohormonal activation, and stimulates the GH/IGF-1 axis in patients with mild to moderate CHF.     

Effects of pravastatin on lipoproteins and endothelial function in patients receiving human immunodeficiency virus protease inhibitors

Background

Although recommended as initial therapy for patients with dyslipidemia who are taking human immunodeficiency virus protease inhibitors (HIV PIs), the effects of pravastatin on lipoproteins and arterial reactivity have not been elucidated. The purpose of this study was to determine the effects of pravastatin on lipoprotein subfractions and endothelial function in patients with dyslipidemia who are receiving HIV PIs.

Methods

This was a placebo-controlled, double-blind, crossover study comparing pravastatin (40 mg) to placebo in 20 patients who were taking HIV PIs. Lipoprotein subfractions were measured with nuclear magnetic resonance spectroscopic analysis. Flow-mediated vasodilation (FMD) of the brachial artery was evaluated with high-resolution ultrasound scanning.

Results

At baseline, subjects had an increased concentration of low-density lipoprotein (LDL) particles (1756 ± 180 nmol/L), which tended to be small (19.9 ± 0.2 nm), a low concentration of large high-density lipoproteins (HDL; 0.94 ± 0.07 mmol/L), and an increased concentration of large very low-density lipoproteins (VLDL; 1.90 ± 0.58 mmol/L). FMD was impaired (4.5% ± 1.1%). Compared with placebo, pravastatin resulted in a 20.8% reduction in LDL particles (P = .030), a 26.7% reduction in small LDL (P = .100), and a 44.9% reduction in small VLDL (P = .023). Total and non-HDL cholesterol levels decreased by 18.3% (P <.001) and 21.7% (P <.001), respectively. FMD tended to increase in patients receiving pravastatin (0.7% ± 0.6%); however, the difference between treatment phases was not statistically significant (P = .080).

Conclusions

This is the first double-blind, placebo-controlled study of the effects of statin therapy on lipids, lipoprotein subfractions, and endothelial function in patients taking HIV PIs. Pravastatin reduced concentrations of atherogenic lipoproteins, particularly those most associated with future coronary events.     

Meta-analysis comparing CT colonography, air contrast barium enema, and colonoscopy

Introduction

Published studies have reported a wide range of sensitivities and specificities for computed tomographic (CT) colonography for polyp detection, generating controversy regarding its diagnostic accuracy.

Methods

A meta-analysis of published studies comparing the accuracies of CT colonography and colonoscopy for polyp detection was performed. The pooled per-patient sensitivities and specificities were calculated at various thresholds for polyp size. Summary receiver operating characteristic (sROC) curves were also constructed.

Results

Thirty studies were included in the meta-analysis of CT colonography. The pooled per-patient sensitivity of CT colonography was higher for polyps greater than 10 mm (0.82, 95% confidence interval [CI], 0.76-0.88) compared with polyps 6 to 10 mm (0.63, 95% CI, 0.52-0.75) and polyps 0 to 5 mm (0.56, 95% CI, 0.42-0.70). Similarly, the exact area under the sROC curve (area ± standard error) was higher using a threshold greater than 10 mm (0.898 ± 0.063) compared with thresholds of greater than 5 mm and any size (0.884 ± 0.033 and 0.822 ± 0.059, respectively). There were no significant differences in the diagnostic characteristics of 2-dimensional versus 3-dimensional CT colonography. At a threshold greater than 5 mm, the exact area under the sROC curve was significantly higher for endoscopic colonoscopy compared with CT colonography (0.998 ± 0.006 vs 0.884 ± 0.033, P < .005).

Conclusions

CT colonography has a reasonable sensitivity and specificity for detecting large polyps but was less accurate than endoscopic colonoscopy for smaller polyps. Thus, CT colonography may not be a reasonable alternative in situations in which a small polyp may be clinically relevant.     

GuardWire emboli protection device is associated with improved myocardial perfusion grade in saphenous vein graft intervention

Background

Use of emboli protection devices (EPD) during saphenous vein graft percutaneous coronary intervention (SVG-PCI) has been proven to reduce major adverse cardiac events (MACE). However, the impact of EPD on the microcirculation using Thrombolysis in Myocardial Infarction myocardial perfusion grade (TMP) has not been fully characterized. We sought to analyze TMP after SVG-PCI with and without EPD and determine its impact on inhospital MACE.

Methods

From August 2001 to December 2002, 305 patients had SVG-PCI suitable for EPD; 210 (69%) had an angiogram appropriate for TMP evaluation. Of those, 46 (22%) had an EPD (GuardWire, Medtronic, Minneapolis, Minn) deployed during the coronary intervention. Both groups were similar with regard to most demographic and clinical features.

Results

A TMP score of 2.5 or 3 was obtained in 98% of the EPD group versus 85% of the unprotected SVG-PCI (P = .01). There was a trend towards reduction in MACE when using EPD (15% vs 27%, respectively, P = .07). Peak postprocedural creatine kinase-MB was somewhat lower in the EPD group (6.03 ± 7.8 ng/mL vs 14.87 ± 42 ng/mL, P = .17) Patients with a TMP grade of 2.5 or 3 had a statistically significant reduction in MACE (OR 0.36, 95% CI 0.14-0.87, P = .02).

Conclusions

Compared with SVG-PCI without emboli protection, EPD significantly improved TMP and trended towards a reduction in MACE.     

Epicardial ablation of right pulmonary artery ganglionated plexi for the prevention of atrial fibrillation originating in the pulmonary veins

Problem Presented

A novel study of catheter ablation of the right pulmonary artery ganglionated plexi (RPA GP) to reduce atrial fibrillation (AF) originating in the pulmonary veins (PVs) is presented.

Studies Undertaken

In 20 dogs, atrial effective refractory periods (AERPs), PVERP, and the dispersion of AERP (dAERP) were measured at baseline during RPA GP stimulation and after ablation. Programmed stimulation and burst stimulation protocols were performed at 4 distal PVs to measure the percentage of AF induced before and after ablation.

Results

Stimulation of the RPA GP shortened AERP (116 ± 16 vs 130 ± 10 milliseconds, P < .01) and PVERP (122 ± 14 vs 136 ± 12 milliseconds, P < .01), and increased dAERP (31 ± 6 vs 23 ± 6 milliseconds, P < .01). However, the above indices revealed an adverse change after excision (AERP, 138 ± 7 vs 130 ± 10 milliseconds; PVERP, 146 ± 18 vs 136 ± 12 milliseconds; and dAERP, 19 ± 5 vs 23 ± 6 milliseconds; P < .05). Furthermore, the percentage of AF induced from PVs was significantly reduced with vagosympathetic stimulation (40% vs 90%, P < .01).

Conclusions

Ablation of the RPA GP changes the electrophysiologic properties of both the atria and the PVs and decreases AF inducibility arising from the PVs.     

Aortic root dysfunctioning and its effect on left ventricular function in Ross procedure patients assessed with magnetic resonance imaging

Background

This study evaluated the diameters and distensibility of the aortic root as well as the degree of aortic regurgitation (AR) and its effect on left ventricular (LV) function in patients 8.2 ± 3.1 years after they underwent the Ross procedure, with a comparison of these parameters between patients and matched healthy subjects.

Methods

Eighteen Ross procedure patients (16 male patients, age [mean ± SD] 19.2 ± 3.8 years) and 18 matched healthy subjects (16 male patients, age [mean ± SD] 19.7 ± 4.2 years) underwent magnetic resonance imaging. Measurements for diameters (at 4 levels) and the distensibility of the aortic root were performed using a steady-state free precession sequence. Aortic flow was assessed with a velocity-encoded phase-contrast sequence. Left ventricular systolic function was assessed with a gradient-echo sequence in the short-axis plane. Comparison of parameters was performed using the Mann-Whitney U test. Correlations between diameters, distensibility, AR fraction, and LV systolic function were expressed with Spearman rank correlation coefficients. Linear regression analysis was used to identify predictors of LV systolic dysfunction.

Results

Aortic root diameters were increased in Ross procedure patients as compared with healthy subjects (mean difference 6.3-11.6 mm, P ≤ .02 at all 4 levels). Distensibility of the aortic root was lower in patients (1.9 ± 1.1 vs 7.8 ± 3.3 mm Hg⁻¹, P < .01). An AR fraction >5% was present in 14 of the 18 patients (mean AR fraction 8% ± 5% vs 1% ± 1%, P < .01). Left ventricular ejection fraction was lower in patients (50% ± 6% vs 57% ± 6%, P < .01). Dilatation, decreased distensibility, and AR fraction were correlated with impaired LV systolic function (P < .05 for all). The AR fraction predicted impaired LV systolic function (P < .01).

Conclusions

Magnetic resonance imaging shows dilatation and decreased distensibility of the aortic root, AR, and consequent impaired LV systolic function in patients after the Ross procedure.     

Body weight changes with beta-blocker use: results from GEMINI

Purpose

Patients with type 2 diabetes are commonly overweight, which can contribute to poor cardiovascular outcomes. β-blockers may promote weight gain, or hamper weight loss, and are a concern in high-risk patients. The current analysis of the Glycemic Effect in Diabetes Mellitus: Carvedilol-Metoprolol Comparison in Hypertensives (GEMINI) trial evaluates the effects of carvedilol and metoprolol tartrate on weight gain in patients with type 2 diabetes and hypertension.

Methods

This prespecified secondary analysis of the GEMINI study (n=1106) evaluated change in body weight after 5 months.

Results

Mean (±SE) baseline weights were 97.5 (±20.1) kg for carvedilol and 96.6 (±20.1) kg for metoprolol tartrate. Treatment difference (c vs m) in mean (±SE) weight change from baseline was −1.02 (±0.21) kg (95% confidence interval [CI], −1.43 to −0.60; P <.001). Patients taking metoprolol had a significant mean (±SE) weight gain of 1.19 (±0.16) kg (P <.001); patients taking carvedilol did not (0.17 [±0.19] kg; P =.36). Metoprolol tartrate-treated patients with body mass index (BMI) >30 kg/m² had a statistically significant greater weight gain than comparable carvedilol-treated patients. Treatment differences (c vs m) in the obese (BMI >30 kg/m²) and morbidly obese groups (BMI >40 kg/m²) were −0.90 kg (95% CI, −1.5 to −0.3; P =.002) and −1.84 kg (95% CI, −2.9 to −0.8; P =.001), respectively. Pairwise correlation analyses revealed no significant associations between weight change and change in HbA_1c, HOMA-IR, or blood pressure.

Conclusions

Metoprolol tartrate was associated with increased weight gain compared to carvedilol; weight gain was most pronounced in subjects with hypertension and diabetes who were not taking insulin therapy.     

Peripheral vascular endothelial function testing for the diagnosis of coronary artery disease

Background

Abnormalities in endothelium-dependent vasodilation may be detected in arteries before the development of overt atherosclerosis, and their presence may predict stress-induced ischemia as assessed by ST-segment depression and/or perfusion defects. Brachial artery ultrasound during reactive hyperemia is a noninvasive method of assessing peripheral vasomotion, measured by flow-mediated vasodilation (FMD). The purpose of the current study was to assess whether endothelium-dependent FMD of the brachial artery, by ultrasound imaging, predicts the presence of angiographically assessed coronary artery disease (CAD).

Methods

One hundred ninety-eight in-hospital patients (age, 59 ± 9 years; 78 women) with chest pain syndrome and without previous myocardial infarction or revascularization procedures were enrolled in the present study. All of the patients, at testing time, were not receiving nitrate therapy and underwent, on different days, coronary angiography and endothelium-dependent FMD testing of the brachial artery by high-resolution ultrasound. The result of the flow-mediated dilation (%FMD) is defined as the percent change in the internal diameter of the brachial artery during reactive hyperemia related to baseline. A coronary vessel was considered to have a significant obstruction if its diameter was narrowed by 50% or more on quantitative computer-assisted analysis. A prognostically validated angiographic Duke score (from 0 = normal to 100 = severe left main disease) was calculated.

Results

The %FMD was lower in patients with (n = 69) compared with those without (n = 129) CAD (4.64% ± 4.36% vs 7.39% ± 5.68%; P = .01). By multivariate analysis, the %FMD (P = .01; odds ratio [OR], 1.13; 95% confidence interval [CI], 1.05 to 1.23), male sex (P = .01; OR, 3.47; 95% CI, 1.64 to 7.36), and cigarette smoking habit (P < .01; OR, 4.00; 95% CI, 2.50 to 6.35) were independent predictors of CAD. %FMD was poorly albeit significantly correlated with the severity of CAD (%FMD Duke score, P < .01, r = −0.25). The receiver operator characteristic curve showed the %FMD optimal cutoff value as ≤8.84, with sensitivity of 90%, specificity of 37%, negative predictive value of 90%, and positive predictive value of 43%.

Conclusions

In patients with chest pain, a depressed FMD of the brachial artery was a sensitive indicator of CAD, but it showed poor specificity, and it appeared to be unable to predict both the extent and the severity of angiographically assessed CAD.