A prospective evaluation of cardiovascular magnetic resonance measures of dyssynchrony in the prediction of response to cardiac resynchronization therapy

Background

Many patients with electrical dyssynchrony who undergo cardiac resynchronization therapy (CRT) do not obtain substantial benefit. Assessing mechanical dyssynchrony may improve patient selection. Results from studies using echocardiographic imaging to measure dyssynchrony have ultimately proved disappointing. We sought to evaluate cardiac motion in patients with heart failure and electrical dyssynchrony using cardiovascular magnetic resonance (CMR). We developed a framework for comparing measures of myocardial mechanics and evaluated how well they predicted response to CRT.

Methods

CMR was performed at 1.5 Tesla prior to CRT. Steady-state free precession (SSFP) cine images and complementary modulation of magnetization (CSPAMM) tagged cine images were acquired. Images were processed using a novel framework to extract regional ventricular volume-change, thickening and deformation fields (strain). A systolic dyssynchrony index (SDI) for all parameters within a 16-segment model of the ventricle was computed with high SDI denoting more dyssynchrony. Once identified, the optimal measure was applied to a second patient population to determine its utility as a predictor of CRT response compared to current accepted predictors (QRS duration, LBBB morphology and scar burden).

Results

Forty-four patients were recruited in the first phase (91% male, 63.3 ± 14.1 years; 80% NYHA class III) with mean QRSd 154 ± 24 ms. Twenty-one out of 44 (48%) patients showed reverse remodelling (RR) with a decrease in end systolic volume (ESV) ≥ 15% at 6 months. Volume-change SDI was the strongest predictor of RR (PR 5.67; 95% CI 1.95-16.5; P = 0.003). SDI derived from myocardial strain was least predictive. Volume-change SDI was applied as a predictor of RR to a second population of 50 patients (70% male, mean age 68.6 ± 12.2 years, 76% NYHA class III) with mean QRSd 146 ± 21 ms. When compared to QRSd, LBBB morphology and scar burden, volume-change SDI was the only statistically significant predictor of RR in this group.

Conclusion

A systolic dyssynchrony index derived from volume-change is a highly reproducible measurement that can be derived from routinely acquired SSFP cine images and predicts RR following CRT whilst an SDI of regional strain does not.     

Compliance in heart failure patients: the importance of knowledge and beliefs.

AIMS: Non-compliance in patients with heart failure (HF) contributes to worsening HF symptoms and may lead to hospitalization. Several smaller studies have examined compliance in HF, but all were limited as they only studied either the individual components of compliance and its related factors or several aspects of compliance without studying the related factors. The aims of this study were to examine all dimensions of compliance and its related factors in one HF population. METHODS AND RESULTS: Data were collected in a cohort of 501 HF patients. Clinical and demographic data were assessed and patients completed questionnaires on compliance, beliefs, knowledge, and self-care behaviour. Overall compliance was 72% in this older HF population. Compliance with medication and appointment keeping was high (>90%). In contrast, compliance with diet (83%), fluid restriction (73%), exercise (39%), and weighing (35%) was markedly lower. Compliance was related to knowledge (OR=5.67; CI 2.87-11.19), beliefs (OR=1.78; CI 1.18-2.69), and depressive symptoms (OR=0.53; CI 0.35-0.78). CONCLUSION: Although some aspects of compliance had an acceptable level, compliance with weighing and exercise were low. In order to improve compliance, an increase of knowledge and a change of patient's beliefs by education and counselling are recommended. Extra attention should be paid to patients with depressive symptoms.     

Geometrical adaptation in ulna and radius of cerebral palsy patients: Measures and consequences

Background

The presence of significant forearm bone torsion might affect planning and evaluating treatment regimes in cerebral palsy patients. We aimed to evaluate the influence of longstanding wrist flexion, ulnar deviation, and forearm pronation due to spasticity on the bone geometries of radius and ulna. Furthermore, we aimed to model the hypothetical influence of these deformities on potential maximal moment balance for forearm rotation.

Methods

Geometrical measures were determined in hemiplegic cerebral palsy patients (n = 5) and healthy controls (n = 5). Bilateral differences between the spastic arm and the unaffected side were compared to bilateral differences between the dominant and non-dominant side in the healthy controls. Hypothetical effects of bone torsion on potential maximal forearm rotation moment were calculated using an existing anatomical muscle model.

Findings

Patients showed significantly smaller (radius: 41.6%; ulna: 32.9%) and shorter (radius: 9.1%; ulna: 8.4%) forearm bones in the non-dominant arm than in the dominant arm compared to controls (radius: 2.4%; ulna 2.5% and radius: 1.5%; ulna: 1.0% respectively). Furthermore, patients showed a significantly higher torsion angle difference (radius: 24.1°; ulna: 26.2°) in both forearm bones between arms than controls (radius: 2.0°; ulna 1.0°). The model predicted an approximate decrease of 30% of potential maximal supination moment as a consequence of bone torsion.

Interpretation

Torsion in the bones of the spastic forearm is likely to influence potential maximal moment balance and thus forearm rotation function. In clinical practice, bone torsion should be considered when evaluating movement limitations especially in children with longstanding spasticity of the upper extremity.     

Experimental studies of some microrheological factors in serious brain ischemia after stobadine pretreatment

Serious brain ischemia was induced by occlusion of cerebral arteries in dogs. The occlusion time was 7 min. The blood was collected at various intervals of reperfusion (5, 60, 180, 240 min and 24 h). Thirty minutes before ischemization, stobadine was given (1, 2, or 5 mg/kg). The changes of erythrocyte membrane fluidity were evaluated using colloid-osmotic hemolysis induced by brilliant cresyl blue. In the control group (without stobadine) the colloid-osmotic hemolysis was significantly increased immediately after ischemization and after 5 and 60 min. However, after 240 min of reperfusion, a significant decrease of hemolysis was observed. The increase of colloidosmotic hemolysis after ischemization in the control group was prevented after stobadine pretreatment. The thrombotization of microcirculation that was observed in the control group was not present after stobadine pretreatment.     

Effect of nephrectomy on vascular renin gene expression and biosynthesis of vascular aldosterone

IthadnotbeenknownthataldosteronecouldbesynthesizedinextraadrcnaltissuesuntilBrilla[ljestablishedthatangiotensinIinducedculturedaorticcellstoproducealdosteronein1992,andthenweconfirmedaldosteronebiosynthesisinvascularcells[Zj.However,itisstillcontroversialwhethertheangiotensinformedintissuesisdependentonreninsynthesizedlocallyorfromplasma.Acarefullydesignedexperimentsuggestedthatcardiacrenindisappeared30hafternephrectomyinhealthypig,andcardiacangiotensinproductionwasdependentonplasma--derivedr…     

Upper extremity musculoskeletal pain during and after rehabilitation in wheelchair-using persons with a spinal cord injury

STUDY DESIGN: Prospective cohort study. OBJECTIVES: To study upper extremity musculoskeletal pain during and after rehabilitation in wheelchair-using subjects with a spinal cord injury (SCI) and its relation with lesion characteristics, muscle strength and functional outcome. SETTING: Eight rehabilitation centers with an SCI unit in the Netherlands. METHODS: Using a questionnaire, number, frequency and seriousness of musculoskeletal pain complaints of the upper extremity were measured. A pain score for the wrist, elbow and shoulder joints was calculated by multiplying the seriousness by the frequency of pain complaints. An overall score was obtained by adding the scores of the three joints of both upper extremities. Muscle strength was determined by manual muscle testing. The motor score of the functional independence measure provided a functional outcome. All outcomes were obtained at four test occasions during and 1 year after rehabilitation. RESULTS: Upper extremity pain and shoulder pain decreased over time (30%) during the latter part of in-patient rehabilitation (P<0.001). Subjects with tetraplegia (TP) showed more musculoskeletal pain than subjects with paraplegia (PP) (P<0.001). Upper extremity pain and shoulder pain were significantly inversely related to functional outcome (P<0.001). Muscle strength was significantly inversely related to shoulder pain (P<0.001). Musculoskeletal pain at the beginning of rehabilitation and BMI were strong predictors for pain 1 year after in-patient rehabilitation (P<0.001). CONCLUSIONS: Subjects with TP are at a higher risk for upper extremity musculoskeletal pain and for shoulder pain than subjects with PP. Higher muscle strength and higher functional outcome are related to fewer upper extremity complaints.     

Effects of early treatment with statins on short-term clinical outcomes in acute coronary syndromes: a meta-analysis of randomized controlled trials

Context  The short-term effects of early treatment with statins in patients after the onset of acute coronary syndromes (ACS) for the outcomes of death, myocardial infarction (MI), and stroke are unclear. Objective  To evaluate relevant outcomes of patients from randomized controlled trials comparing early statin therapy with placebo or usual care at 1 and 4 months following ACS. Data Sources and Study Selection  Systematic search of electronic databases (MEDLINE, EMBASE, PASCAL, Cochrane Central Register) from their inception to August 2005, which was supplemented by contact with experts in the field. Two reviewers independently determined the eligibility of randomized controlled trials that compared treatment with statins with a control, were initiated within 14 days after onset of ACS, and had a minimal follow-up of 30 days. Trials with cerivastatin were only included in a sensitivity analysis. Data Extraction  Information on baseline characteristics of included trials and patients, reported methodological quality, lipid levels, and clinical outcome was independently extracted by 2 investigators. Investigators from each included trial contributed additional data if necessary. Data Synthesis  Twelve trials involving 13 024 patients with ACS were included in the meta-analysis. The risk ratios for the combined end point of death, MI, and stroke for patients treated with early statin therapy compared with control therapy were 0.93 (95% confidence interval [CI], 0.80-1.09; P = .39) at 1 month and 0.93 (95% CI, 0.81-1.07; P = .30) at 4 months following ACS. There were no statistically significant risk reductions from statins for total death, total MI, total stroke, cardiovascular death, fatal or nonfatal MI, or revascularization procedures (percutaneous coronary intervention or coronary artery bypass graft surgery). Sensitivity analyses with restriction to trials of high quality or with additional data from a large trial using cerivastatin indicated summary risk ratios even closer to 1. Conclusion  Based on available evidence, initiation of statin therapy within 14 days following onset of ACS does not reduce death, MI, or stroke up to 4 months.