Comparison between myocardial integrated backscatter and strain rate imaging in the quantitative assessment of subepicardial function post-myocardial infarction

Transmural extent of infarction (TME) may be an important determinant of functional recovery and remodeling. Recent animal data suggest that strain rate imaging (SRI) maybe able to identify subendocardial ischemia.We compared SRI and cyclic variation of integrated backscatter (CVIB) for predicting TME in the quantitative assessment of regional subepicardial function. Forty-nine (n = 49) postmyocardial infarct patients (61±10 years, EF 41±10%) underwent tissue Doppler echocardiography (TDE) and contrast enhanced magnetic resonance imaging (CMR). A15 mm×2mm sampling volume (tracked to wall motion) was placed over the long axis subepicardial region of each segment during TDE offline analysis to measure peak longitudinal systolic strain rate (SR), peak longitudinal systolic strain (PS), and CVIB. Findingswere compared with TME classified into two categories of scar thickness by CMR: Non-transmural (TME≤50%), and transmural (TME > 50%). Of 213 segments identified with resting wall motion abnormalities, 145 segments showed delayed hyperenhancement on CMR. SR, PS and CVIB were similar with no significant differences between transmural and non-transmural infarcts regardless of the echo modality.

Reduction in scar thickness post myocardial infarction is secondary to increase in regional left ventricular volumes

We sought to determine the relative impact of myocardial scar and viability on post-infarct left ventricular (LV) remodeling in medically-treated patients with LV dysfunction. Forty patients with chronic ischemic heart disease (age 64±9, EF 40±11%) underwent rest-redistribution Tl201 SPECT (scar = 50% transmural extent), A global index of scarring for each patient (CMR scar score) was calculated as the sum of transmural extent scores in all segts. LV end diastolic volumes (LVEDV) and LV end systolic volumes (LVESV) were measured by real-time threedimensional echo at baseline and median of 12 months follow-up. There was a significant positive correlation between change in LVEDV with number of scar segts by all three imaging techniques (LVEDV: SPECT scar, r = 0.62, p < 0.001; DbE scar, r = 0.57, p < 0.001; CMR scar, r = 0.52, p < 0.001) but change in LV volumes did not the correlate with number of viable segments. ROC curve analysis showed that remodeling (LVEDV> 15%) was predicted bySPECTscars(AUC= 0.79),DbEscars(AUC= 0.76),CMR scars (AUC= 0.70), and CMR scar score (AUC 0.72). There were no significant differences between any of the ROC curves (Z score

Depression and cardiovascular morbidity and mortality: cause or consequence?

Background Depression after myocardial infarction has been associated with increased cardiovascular mortality. This study assessed whether depressive symptoms were associated with adverse outcomes in people with a history of an acute coronary syndrome, and evaluated possible explanations for such an association. Methods and results Depressive symptoms were assessed using the General Health Questionnaire at least 5 months after hospital admission for acute myocardial infarction or unstable angina in 1130 participants of the Long-Term Intervention with Pravastatin in Ischaemic Disease (LIPID) Study, a multicentre, placebo-controlled, clinical trial of cholesterol-lowering treatment. Cardiovascular symptoms, self-rated general health, cardiovascular risk factors, employment status, social support and life events were also assessed at the baseline visit. Cardiovascular death (n=114), non-fatal myocardial infarction (n=108), non-fatal stroke (n=53) and unstable angina (n=274) were documented during a median follow-up period of 8.1 years. Individuals with depressive symptoms (General. Health Questionnaire score greater than or equal to5; 22% of participants) were more likely to report angina, dyspnoea, claudication, poorer general health, not being in paid employment, few social contacts and/or adverse life events (P

Are diagnosis specific outcome indicators based on administrative data useful in assessing quality of hospital care?

Background: Hospital performance reports based on administrative data should distinguish differences in quality of care between hospitals from case mix related variation and random error effects. A study was undertaken to determine which of 12 diagnosis-outcome indicators measured across all hospitals in one state had significant risk adjusted systematic ( or special cause) variation (SV) suggesting differences in quality of care. For those that did, we determined whether SV persists within hospital peer groups, whether indicator results correlate at the individual hospital level, and how many adverse outcomes would be avoided if all hospitals achieved indicator values equal to the best performing 20% of hospitals. Methods: All patients admitted during a 12 month period to 180 acute care hospitals in Queensland, Australia with heart failure (n = 5745), acute myocardial infarction ( AMI) ( n = 3427), or stroke ( n = 2955) were entered into the study. Outcomes comprised in-hospital deaths, long hospital stays, and 30 day readmissions. Regression models produced standardised, risk adjusted diagnosis specific outcome event ratios for each hospital. Systematic and random variation in ratio distributions for each indicator were then apportioned using hierarchical statistical models. Results: Only five of 12 (42%) diagnosis-outcome indicators showed significant SV across all hospitals ( long stays and same diagnosis readmissions for heart failure; in-hospital deaths and same diagnosis readmissions for AMI; and in-hospital deaths for stroke). Significant SV was only seen for two indicators within hospital peer groups ( same diagnosis readmissions for heart failure in tertiary hospitals and inhospital mortality for AMI in community hospitals). Only two pairs of indicators showed significant correlation. If all hospitals emulated the best performers, at least 20% of AMI and stroke deaths, heart failure long stays, and heart failure and AMI readmissions could be avoided. Conclusions: Diagnosis-outcome indicators based on administrative data require validation as markers of significant risk adjusted SV. Validated indicators allow quantification of realisable outcome benefits if all hospitals achieved best performer levels. The overall level of quality of care within single institutions cannot be inferred from the results of one or a few indicators.

Effects of revascularisation and contractile reserve on left ventricular remodelling in patients with impaired left ventricular function

Objective: We sought to define the influence of revascularisation and contractile reserve on left ventricular (LV) remodelling in patients with LV dysfunction after myocardial infarction. Revascularisation of viable myocardium is associated with improved regional function, but the effect on remodelling is undefined. Methods: We studied 70 patients with coronary artery disease and LV dysfunction, 31 of whom underwent revascularisation. A standard dobutamine stress echocardiogram (DbE) was carried out. All patients underwent standard medical treatment; the decision to revascularise was made clinically, independent of this study. LV volumes and ejection fraction were measured by 3D echocardiography at baseline and after an average of 40 weeks. Results: There was no significant difference in baseline ejection fraction or volumes between patients who underwent revascularisation and the remainder. Compared to medically treated patients, revascularised patients had significant improvements in ejection fraction and end-systolic volume in follow-up. The impact of baseline variables on remodelling was assessed by dividing patients into tertiles of LV ejection fraction and volumes. Revascularised patients in the lowest tertile of ejection fraction at baseline (<38%) had a significant improvement in end-systolic volume and ejection fraction, larger than obtained in medically treated patients with low ejection fraction. Revascularised patients with an ejection fraction >38% did not show significant improvement in volumes compared to baseline. Revascularised patients in the largest tertiles of end-systolic (>88 ml) or end-diastolic volume (>149 ml) at baseline had a significant improvement in end-systolic volume. Conclusion: Remodeling appears to occur independent of the presence of regional contractile reserve but does correlate with the volume response to low-dose dobutamine. (C) 2003 Elsevier Ireland Ltd. All rights reserved.

Multisite, quality-improvement collaboration to optimise cardiac care in Queensland public hospitals

Objective: To evaluate changes in quality of in-hospital care of patients with either acute coronary syndromes (ACS) or congestive heart failure (CHF) admitted to hospitals participating in a multisite quality improvement collaboration. Design: Before-and-after study of changes in quality indicators measured on representative patient samples between June 2001 and January 2003. Setting: Nine public hospitals in Queensland. Study populations: Consecutive or randomly selected patients admitted to study hospitals during the baseline period (June 2001 to January 2002; n = 807 for ACS, n = 357 for CHF) and post-intervention period (July 2002 to January 2003; n = 717 for ACS, n = 220 for CHF). Intervention: Provision of comparative baseline feedback at a facilitative workshop combined with hospital-specific quality-improvement interventions supported by on-site quality officers and a central program management group. Main outcome measure: Changes in process-of-care indicators between baseline and post-intervention periods. Results: Compared with baseline, more patients with ACS in the post-intervention period received therapeutic heparin regimens (84% v 72%; P < 0.001), angiotensin-converting enzyme inhibitors (64% v 56%; P = 0.02), lipid-lowering agents (72% v 62%; P < 0.001), early use of coronary angiography (52% v 39%; P < 0.001), in-hospital cardiac counselling (65% v 43%; P < 0.001), and referral to cardiac rehabilitation (15% v 5%; P < 0.001). The numbers of patients with CHF receiving β-blockers also increased (52% v 34%; P < 0.001), with fewer patients receiving deleterious agents (13% v 23%; P = 0.04). Same-cause 30-day readmission rate decreased from 7.2% to 2.4% (P = 0.02) in patients with CHF. Conclusion: Quality-improvement interventions conducted as multisite collaborations may improve in-hospital care of acute cardiac conditions within relatively short time frames.

Using clinical indicators in a quality improvement programme targeting cardiac care

Rationale. The Brisbane Cardiac Consortium, a quality improvement collaboration of clinicians from three hospitals and five divisions of general practice, developed and reported clinical indicators as measures of the quality of care received by patients with acute coronary syndromes or congestive heart failure. Development of indicators. An expert panel derived indicators that measured gaps between evidence and practice. Data collected from hospital records and general practice heart-check forms were used to calculate process and outcome indicators for each condition. Our indicators were reliable (kappa scores 0.7-1.0) and widely accepted by clinicians as having face validity. Independent review of indicator-failed, in-hospital cases revealed that, for 27 of 28 process indicators, clinically legitimate reasons for withholding specific interventions were found in

Do risk factors for lactic acidosis influence dosing of metformin?

Background: Metformin is commonly prescribed to treat type 2 diabetes mellitus, however it is associated with the potentially lethal condition of lactic acidosis. Prescribing guidelines have been developed to minimize the risk of lactic acidosis development, although some suggest they are inappropriate and have created confusion amongst prescribers. The aim of this study was to investigate whether metformin dose was influenced by the presence of risk factors for lactic acidosis. Methods: The study was prospective, and retrieved information from patients admitted to hospital who were prescribed metformin at their time of admission. Results: Eighty-three patients were included in the study, 60 of whom had a least one risk factor for lactic acidosis. Of those 60 patients, 78.3% had a dose adjustment, with renal impairment, hepatic impairment, surgery and use of radiological contrast media - the risk factors most likely to result in a dose adjustment. When dose adjustments did occur, metformin was withheld on 88.7% of occasions. Conclusion: Metformin dose was influenced by the presence of risk factors for lactic acidosis, although it was dependent upon the number and particular risk factor/s present.

Survey of intensive care nurses' knowledge relating to the pulmonary artery catheter

In 2003 there was an increase in the use of pulmonary artery catheters in Australia from 12, 000 to 16, 000 units in intensive care and peri-operative care. This survey of intensive care nurses in five intensive care units in Queensland addressed knowledge of use, safety and complications of the pulmonary artery catheter, using a previously validated 31 question multiple choice survey. One hundred and thirty-nine questionnaires were completed, a response rate of 46%. The mean score was 13.3, standard deviation +/-4.2 out of a total of 31 (42.8% correct). The range was 4 to 25. Scores were significantly higher in those participants with more ICU experience, higher nursing grade, a higher self-assessed level of knowledge and greater frequency of PAC supervision. There was no significant correlation between total score and hospital- or university-based education, or total score and public or private hospital participants. Fifty-one per cent were unable to correctly identify the significant pressure change as the catheter is advanced from the right ventricle to the pulmonary artery.

Is the increase in coronary events on Mondays an artifact?

Background: The aim of this article was to investigate the size and possible causes of the reported excess in coronary events on Mondays. Methods: We conducted a metaanalysis of data from the World Health Organization (WHO) MONICA Project, which monitored trends and determinants in cardiovascular disease. The MONICA Project was undertaken in 21 countries from 1980 to 1995. Results: We found a small overall excess rate of coronary events on Mondays. In a population experiencing 100 events per week, we estimate there would be approximately I more event on Monday than on any other day. Hierarchical logistic regression showed that the Monday excess was greater in centers with less thorough data collection procedures. Conclusions: The excess of coronary events on Mondays is probably an artifact resulting from events with uncertain dates being coded as taking place on Mondays.