Usefulness of the Mitral Regurgitation Severity Index to Assess the Severity of Chronic Mitral Regurgitation.

Existing metrics for grading mitral regurgitation (MR) are limited and fraught with high interobserver variability. We developed and evaluated a Doppler-based, semiquantitative novel index (Mitral Regurgitation Severity Index [MRSI]) of MR severity. In a total of 125 patients (70 in the derivation cohort and 55 in the validation cohort), MRSI was calculated as a ratio of time velocity integral of mitral inflow (continuous-wave Doppler-TVI MV) to the time velocity integral of the left ventricle outflow (pulse-wave Doppler-TVI LVOT). Inter-rater agreement for MRSI and predictive ability of the MRSI were then assessed. In the derivation cohort, MRSI differed significantly between patients with severe MR (2.6 ± 0.51) and mild-moderate (nonsevere) MR (1.4 ± 0.18) and a cutoff of ≥1.8 was associated with optimal diagnostic accuracy. In the validation cohort, MRSI exhibited excellent agreement between a level II and a level III reader with a mean difference of -0.14 (95% confidence limit of agreement: -0.80 to 0.53), correlation coefficient of 0.88 (p <0.001), and 16% CV; and using the cut point of 1.8, it exhibited good inter-rater reproducibility with a kappa coefficient of 0.72 (p <0.001). In conclusion, MRSI appears to be a simple, quantitative, practical, color-independent metric to differentiate severe MR from nonsevere MR.

Long (>12 Months) and Short (<6 Months) Versus Standard Duration of Dual Antiplatelet Therapy After Coronary Stenting: A Systematic Review and Meta-Analysis.

Dual antiplatelet therapy (DAPT) is recommended for 6-12 months after drug-eluting stent (DES) implantation to prevent ischemic events and late stent thrombosis. The optimal duration of DAPT has not been established. We performed a meta-analysis of the comparative effects of short and long versus standard duration DAPT duration on adverse cardiovascular and major bleeding. We conducted an EMBASE and MEDLINE search for studies in which patients were randomized to treatment with a different duration of DAPT. We included studies that provided data on DES selection, DAPT regimen and duration, and incidence of the selected endpoints at the end of the follow-up period. We identified 5 prospective randomized studies comparing short versus standard duration DAPT and 3 comparing long versus standard duration DAPT with a total of 28,343 patients. Short-term DAPT has similar incidence of stent thrombosis, MI, and death compared to standard duration DAPT, whereas major bleeding was significantly lower in short duration DAPT. Long-term DAPT was associated with lower rates of stent thrombosis and MI but significantly increased major bleeding and all-cause mortality compared to standard duration DAPT. In this meta-analysis of prospective controlled studies we found that short duration DAPT is safer and as effective as standard duration DAPT in patients with second-generation DES. Extended DAPT is associated with less ischemic events at the expense of high bleeding and mortality rates.

Comparison of right ventricular contractile abnormalities in hypertrophic cardiomyopathy versus hypertensive heart disease using two dimensional strain imaging: a cross-sectional study.

Hypertrophic cardiomyopathy (HCM) affects the right ventricle (RV) because of the anatomically hypertrophied septum and plausibly by extension of the myopathic process to the RV. We sought to investigate RV strain in patients with left ventricular hypertrophy secondary to either HCM or hypertension (H-LVH). Our cross-sectional study included 32 patients with HCM, 21 patients with H-LVH, and 11 healthy subjects, who were evaluated with transthoracic echocardiography. Using a dedicated software package, bi-dimensional acquisitions were analyzed to measure segmental longitudinal strain in apical views. Right ventricular global longitudinal strain (GLS) was calculated by averaging septal and right free wall strains. The HCM and H-LVH groups were comparable for age and demographic characteristics. Right ventricular tricuspid annular plane systolic excursion was not significantly different between HCM and H-LVH subjects. Moreover, RV GLS, septal and lateral RV myocardial strain were significantly impaired in patients with HCM (all p < 0.001). Regional and global RV strain parameters were not significantly impaired in H-LVH compared to healthy controls An RV GLS cut-off value of >14.9% differentiated HCM and H-LVH with a 90% sensitivity and a 95% specificity (p < 0.001). RV strain parameters are impaired in patients with HCM. Assessment of two-dimensional RV strain parameters could help differentiate between HCM and H-LVH.

Myocardial fibrosis on cardiac magnetic resonance and cardiac outcomes in hypertrophic cardiomyopathy: a meta-analysis.

OBJECTIVE: Late gadolinium enhancement (LGE) on cardiac MRI that indicates the extent of myocardial fibrosis in hypertrophic cardiomyopathy (HCM) is a potential risk factor of sudden cardiac death (SCD) in non-high-risk patients according to conventional clinical markers. METHODS: The present study was designed to systematically review prospective trials and assess the association between LGE and SCD in HCM. We systematically searched the electronic databases, MEDLINE, PubMed, Embase and Cochrane for prospective cohort studies of the effects of LGE on clinical outcomes (SCD/aborted SCD, all-cause mortality, cardiac and heart failure death) in HCM. RESULTS: We identified six clinical studies, examining 1414 patients without LGE and 1653 with LGE and an average follow-up of 3.05 years. The incidence of SCD/aborted SCD in patients with HCM and LGE was significantly increased as compared with patients without LGE (OR 2.52, 95% CI 1.44 to 4.4, p=0.001). The all-cause mortality and cardiac death rates were also significantly increased in patients with LGE. The extent of LGE was not significantly related to the risk of SCD. CONCLUSIONS: LGE is significantly associated with SCD risk, cardiac mortality and all-cause mortality in patients with non-high-risk HCM according to conventional risk factors.

Is bacteriostatic saline superior to normal saline as an echocardiographic contrast agent?

Objective data on the performance characteristics and physical properties of commercially available saline formulations [normal saline (NS) vs. bacteriostatic normal saline (bNS)] are sparse. This study sought to compare the in vitro physical properties and in vivo characteristics of two commonly employed echocardiographic saline contrast agents in an attempt to assess superiority. Nineteen patients undergoing transesophageal echocardiograms were each administered agitated regular NS and bNS injections in random order and in a blinded manner according to a standardized protocol. Video time-intensity (TI) curves were constructed from a representative region of interest, placed paraseptally within the right atrium, in the bicaval view. TI curves were analyzed for maximal plateau acoustic intensity (Vmax, dB) and dwell time (DT, s), defined as time duration between onset of Vmax and decay of video intensity below clinically useful levels, reflecting the duration of homogenous opacification of the right atrium. To further characterize the physical properties of the bubbles in vitro, fixed aliquots of similarly agitated saline were injected into a glass well slide-cover slip assembly and examined using an optical microscope to determine bubble diameter in microns (µm) and concentration [bubble count/high power field (hpf)]. A higher acoustic intensity (a less negative dB level), higher bubble concentration and longer DT were considered properties of a superior contrast agent. For statistical analysis, a paired t test was conducted to evaluate the differences in means of Vmax and DT. Compared to NS, bNS administration was associated with superior opacification (video intensity -8.69 ± 4.7 vs. -10.46 ± 4.1 dB, P = 0.002), longer DT (17.3 ± 6.1 vs. 10.2 ± 3.7 s) in vivo and smaller mean bubble size (43.4 vs. 58.6 µm) and higher bubble concentration (1,002 vs. 298 bubble/hpf) in vitro. bNS provides higher intensity and more sustained opacification of the right atrium compared to NS. Higher bubble concentration and stability appear to be additional desirable rheological characteristics favoring bNS as a contrast agent.

Effect of long-term exposure to lower low-density lipoprotein cholesterol beginning early in life on the risk of coronary heart disease: a Mendelian randomization analysis.

OBJECTIVES: The purpose of this study was to estimate the effect of long-term exposure to lower plasma low-density lipoprotein cholesterol (LDL-C) on the risk of coronary heart disease (CHD). BACKGROUND: LDL-C is causally related to the risk of CHD. However, the association between long-term exposure to lower LDL-C beginning early in life and the risk of CHD has not been reliably quantified. METHODS: We conducted a series of meta-analyses to estimate the effect of long-term exposure to lower LDL-C on the risk of CHD mediated by 9 polymorphisms in 6 different genes. We then combined these Mendelian randomization studies in a meta-analysis to obtain a more precise estimate of the effect of long-term exposure to lower LDL-C and compared it with the clinical benefit associated with the same magnitude of LDL-C reduction during treatment with a statin. RESULTS: All 9 polymorphisms were associated with a highly consistent reduction in the risk of CHD per unit lower LDL-C, with no evidence of heterogeneity of effect (I(2) = 0.0%). In a meta-analysis combining nonoverlapping data from 312,321 participants, naturally random allocation to long-term exposure to lower LDL-C was associated with a 54.5% (95% confidence interval: 48.8% to 59.5%) reduction in the risk of CHD for each mmol/l (38.7 mg/dl) lower LDL-C. This represents a 3-fold greater reduction in the risk of CHD per unit lower LDL-C than that observed during treatment with a statin started later in life (p = 8.43 × 10(-19)). CONCLUSIONS: Prolonged exposure to lower LDL-C beginning early in life is associated with a substantially greater reduction in the risk of CHD than the current practice of lowering LDL-C beginning later in life.

Effect of long-term monotherapy with the aldosterone receptor blocker eplerenone on cytoskeletal proteins and matrix metalloproteinases in dogs with heart failure.

PURPOSE: Long-term monotherapy with the aldosterone receptor blocker eplerenone in dogs with HF was previously shown to improve LV systolic and diastolic function. This study examined the effects of long-term monotherapy with the aldosterone receptor blocker eplerenone on mRNA and protein expression of the cytoskeletal proteins titin, tubulin, fibronectin and vimentin, the matrix metalloproteinases (MMPs)-1, -2 and -9, and the tissue inhibitors of MMPs (TIMPs)-1 and -2 in left ventricular (LV) myocardium of dogs with heart failure (HF). METHODS: HF was produced in 12 dogs by intracoronary microembolizations. Dogs were randomized to 3 months oral therapy with eplerenone (10 mg/kg twice daily, n = 6) or to no therapy at all (HF-control, n = 6). LV tissue from six normal dogs was used for comparison. mRNA expression was measured using reverse-transcriptase polymerase chain reaction (RT-PCR) and protein expression using Western blots. RESULTS: Compared to NL dogs, control dogs showed upregulation of mRNA and protein expression for tubulin, fibronectin, MMP-1, -2 and -9, and down-regulation of mRNA and protein expression for total titin. Normalization of mRNA and protein expression for all these genes was seen after treatment with eplerenone. N2BA/N2B-titin mRNA expression ratio increased significantly in dogs with HF treated with eplerenone. No differences in expression for vimentin, TIMP-1 and -2 were observed among groups. CONCLUSIONS: In dogs with HF, long-term eplerenone therapy normalizes mRNA and protein expression of key cytoskeletal proteins and MMPs. Reversal of these molecular maladaptations may partly explain the improvement in LV diastolic function seen after long-term therapy with eplerenone.

Catheter-directed thrombolysis (intrathrombus injection) in treatment of deep venous thrombosis: a systematic review.

Methods of delivery of thrombolytic agents for massive or limb threatening deep venous thrombosis (DVT) include a systemic infusion, local-regional administration, and catheter-directed therapy (tip of catheter placed inside the thrombus). We evaluated the effectiveness of catheter-directed therapy and compared the results with randomized clinical trials of systemic and local-regional thrombolytic therapy. Many who used catheter-directed thrombolysis used balloon angioplasty, stents, or thrombectomy in addition. Pooled data showed higher rates of complete early opening of occluded veins with catheter-directed thrombolysis alone, 90%, or with catheter-directed thrombolysis often followed by adjunct therapy, 76%, than with a systemic infusion, 28%, or local-regional administration, 20%. The prevalence of postthrombotic syndrome was lower with catheter-directed combined with adjunct therapy, 26%, compared with 56% and 69%, respectively. Rates of any bleeding were higher with catheter-directed thrombolytic therapy, but bleeding was usually minor. In conclusion, the data suggest that catheter-directed thrombolytic therapy may be more beneficial than systemic or local regional administration. An advantage is that it lends itself to adjunct treatment following the administration of thrombolytic agents if the thrombolysis is inadequate.

Risk of venous thromboembolism in patients hospitalized with heart failure.

Because of uncertainty about the prevalence of pulmonary embolism (PE) and deep venous thrombosis (DVT) in hospitalized patients with congestive heart failure (CHF), data from the National Hospital Discharge Survey were investigated. Among hospitalized patients with CHF, PE was diagnosed in 0.73% and DVT in 1.03%. The relative risk for PE in patients with CHF compared with patients with no CHF was 2.15; for DVT, it was 1.21. The relative risk for PE in patients with CHF was greatest in patients <40 years of age (relative risk 11.72), and the relative risk for DVT was 5.46. In conclusion, a high relative risk for PE, DVT, and venous thromboembolism was shown in patients with CHF who were <60 years of age.

Usefulness of 4-, 8-, and 16-slice computed tomography for detection of graft occlusion or patency after coronary artery bypass grafting.

The sensitivity and specificity of computed tomographic angiography for the evaluation of coronary artery bypass grafts (CABGs) was reviewed. A search of published studies in all languages was performed, incorporating electronic and manual components. A total of 985 patients with 2,200 CABGs participated in investigations with single-detector computed tomography (CT), 441 patients (1,246 CABGs) with 4-slice CT, none with 8-slice CT, and 144 patients (416 grafts) with 16-slice CT. Pooled data showed a sensitivity for the detection of complete occlusion with single-slice CT of 81% (402 of 494 patients), with 4-slice CT of 93% (293 of 315 patients), and with 16-slice CT of 99% (75 of 76 patients). The specificity, based on pooled data, using single-slice CT was 89% (1,507 of 1,697 patients), with 4-slice CT was 96% (878 of 915 patients), and with 16-slice CT was 98% (301 of 306 patients). The detection of complete occlusion and the detection of patency in saphenous vein bypass grafts and arterial bypass grafts were similar with multislice CT. Limited data were available on the detection of significant stenosis, exclusive of complete occlusion. With 4-slice CT, the sensitivity was 74% (23 of 31 patients) and was 88% (21 of 24 patients) with 16-slice CT. In conclusion, single-detector CT was able to detect graft patency, but it was not sensitive for graft occlusion. The data suggest that 4- and 16-slice CT can be used for the detection of complete graft occlusion or graft patency of CABGs. Significant stenosis was better assessed with 16-slice CT than with 4-slice CT.

Mortality from acute pulmonary embolism according to season.

BACKGROUND: Varying observations have been made on seasonal differences of mortality from acute pulmonary embolism (PE). METHODS: The number of deaths each year from PE, from 1980 through 1998, based on death certificates, was obtained from the US National Center for Health Statistics Multiple Cause-of-Death Files. RESULTS: Acute PE as the cause of death ranged from 0.91 to 1.03 PE deaths per quarter per 100,000 population. Small differences were statistically significant due to the large number of patients evaluated. Quarterly mortality rates from PE in the northeast, south, midwest, and west, where seasonal weather varies widely, showed no meaningful seasonal differences. CONCLUSION: Mortality rates from PE do not vary to a meaningful extent according to season.