P1758The novel small leucin-rich repeat protein podocan is an independent predictor of major adverse cardiac events in patients with angiographically-defined coronary artery disease

Background

Smooth muscle cell (SMC) function determines the clinical course of vascular disease via fibrous cap stability. Podocan is an inhibitor of SMC function and is circulating in peripheral blood rendering it a candidate biomarker to predict MACE in patients with Coronary Artery Disease (CAD).

Purpose

We designed a prospective cohort study assessing the predictive value of Podocan for cardiovascular outcome (MI, CVA or death) in patients with CAD.

Methods

308 patients with angiographic evidence of CAD were enrolled. At index cardiac catheterization Syntax Score was calculated. For patient baseline characteristics see Table. Podocan and CRP-1 were measured using a human Podocan and CRP-1 ELISA. The Kaplan-Meier method was used to construct survival curves, which were compared using the log-rank test. Cox proportional hazard modeling was used for all univariate/multivariate analyses. Statistical analysis was performed using STATA.

Results

Podocan was detected in 212 patients (69%) with a detection threshold of 0.01 ng/ml. The median Podocan level observed was 1.4±8.2 ng/ml. 96 patients did not have a detectable Podocan level. Mean CRP-1 was 0.117±0.15 mg/ml. Mean Syntax Score was 12±9. Podocan did not correlate with CRP-1. There was also no association between Podocan and Syntax Score, age, BMI, smoking, LDL, and HDL, HgbA1c, LVEF and GFR. At the univariate level, presence of Podocan was associated with an increased rate of MACE (17% Podocan present vs. 7% Podocan absent, p=0.02). Kaplan-Meier survival analysis showed higher event free survival in patients with no detectable Podocan vs. detectable Podocan level (Figure). In a limited multivariate Cox proportional Hazard analysis, Podocan remained an independent predictor of MACE (HR: 2.5; P=0.042) in addition to diabetes, and LV ejection fraction.

Baseline Characteristics Total (N=308) Chronic ischemic heart disease (N=273) Acute coronary syndrome (N=35) Age (Year) 66.5±9.5 67±9 61±11 Female (Sex) 106 (33%) 90 (31%) 16 (46%) Hypertension 282 (89%) 244 (89%) 26 (74%) Diabetes 142 (44%) 124 (45%) 11 (31%) Hyperlipidemia 269 (87%) 243 (89%) 26 (74%) CRP (mg/dL) 0.11±0.14 0.10±0.13 0.18±0.19 LVEF (%) 49±10 49±10 48±9.5 CRP, C-reactive protein; LVEF, Left ventricular ejection fraction.

Kaplan Meier Survival Curves by Podocan

Conclusion

Podocan is a novel biomarker independently predicting MACE in secondary prevention of CAD warranting to be further studied in a Multicenter Clinical Trial.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Provision, uptake and cost of cardiac rehabilitation programmes: improving services to under-represented groups

OBJECTIVES

To estimate UK need for outpatient cardiac rehabilitation, current provision and identification of patient groups not receiving services. To conduct a systematic review of literature on methods to improve uptake and adherence to cardiac rehabilitation. To estimate cost implications of increasing uptake of cardiac rehabilitation.

DATA SOURCES

Hospital Episode Statistics (England). Hospital Inpatient Systems (Northern Ireland). Patients Episode Database for Wales. British Association for Cardiac Rehabilitation/British Heart Foundation surveys. Cardiac rehabilitation centres. Patients from general hospitals. Electronic databases.

REVIEW METHODS

The study analysed hospital discharge statistics to ascertain the population need for outpatient cardiac rehabilitation in the UK. Surveys of cardiac rehabilitation programmes were conducted to determine UK provision, uptake and audit activity, and to identify local interventions to improve uptake. Data were also examined from a trial estimating eligibility for cardiac rehabilitation and non-attendance. A systematic review of interventions to improve patient uptake, adherence and professional compliance in cardiac rehabilitation was conducted. Estimated costs of improving uptake were identified from national survey, systematic review and sampled cardiac rehabilitation programmes.

RESULTS

In England, Wales and Northern Ireland nearly 146,000 patients discharged from hospital with primary diagnosis of acute myocardial infarction, unstable angina or following revascularisation were potentially eligible for cardiac rehabilitation. In England in 2000, 45-67% of these patients were referred, with 27-41% attending outpatient cardiac rehabilitation. If all discharge diagnoses of ischaemic heart disease were considered, nearly 299,000 patients would be potentially eligible and in England rates of attendance and referral would be 22-33% and 13-20% respectively. Rates of referral and attendance were similar in Wales, but somewhat lower in Northern Ireland. It was found that referral and attendance of older people and women at cardiac rehabilitation tended to be low. It was also suggested that patients from ethnic minorities and those with angina or heart failure were less likely to be referred to or join programmes. A wide range of local interventions suggested awareness of the problem of uptake. In an NHS-funded randomised controlled trial, possibly representing more optimal protocol-led care, medical and nursing staff identified 73-81% of patients with acute myocardial infarction as eligible for cardiac rehabilitation. Excluded patients tended to be older with more severe presentation of cardiac disease. Experiences of patients suggested that uptake may be improved by addressing issues of motivation and relevance of rehabilitation to future well-being, co-morbidities, site and time of programme, transport and care for dependents. Systematic review of studies supported the use of letters, pamphlets or home visits to motivate patients and the use of trained lay visitors. Self-management techniques showed some value in promoting adherence to lifestyle changes. Studies examining professional compliance found that professional support for practice nurses may have value in the coordination of postdischarge care. Average costs in 2001 of cardiac rehabilitation to the health service per patient completing a cardiac rehabilitation programme were about GBP350 (staff only) and GBP490 (total). If services were modelled on an intermediate multidisciplinary configuration with three to five key staff, approximately 13% more patients could be treated with the same budget. Depending on staffing configuration an approximate 200-790% budget increase would be required to provide cardiac rehabilitation to all potentially eligible patients.

CONCLUSIONS

Provision of outpatient cardiac rehabilitation in the UK is low and little is known about the capacity of cardiac rehabilitation centres to increase this provision. There is an uncoordinated approach to audit data collection and few interventions aimed at improving the situation have been formally evaluated. Motivational communications and trained lay volunteers may improve uptake of cardiac rehabilitation, as may self-management techniques. Experience of low-cost interventions and good practice exists within rehabilitation centres, although cost information frequently is not reported. Increased provision of outpatient cardiac rehabilitation will require extra resources. Further trials are required to compare the cost-effectiveness of comprehensive multidisciplinary rehabilitation with simpler outpatient programmes, also research is needed into economic and patient preference studies of the effects of different methods of using increased funding for cardiac rehabilitation. An evaluation of a range of interventions to promote attendance in all patients and under-represented groups would also be useful. The development of standards is suggested for audit methods and for eligibility criteria, as well as regular and comprehensive data collection to estimate the need for and provision of cardiac rehabilitation. Further areas for intervention could be identified through qualitative studies, and the extension of low-cost interventions and good practice within rehabilitation centres. Regularly updated systematic reviews of relevant literature would also be useful.

Hysteresis of left ventricular end ejection pressure-dimension relations after acute pressure loading in the intact canine heart

The left ventricular end systolic pressure-volume relation of the isolated canine heart is linear and independent of the loading conditions. The effects of acute pressure loading on the left ventricular end ejection pressure-length relations were studied in the intact canine heart. The lengths of two wall segments of the left ventricle parallel to the minor axis were measured with pairs of miniature piezoelectric crystals. At two levels of filling pressure, with and without control of heart rate, acute increases in left ventricular afterload were produced for six successive beats by occluding the thoracic aorta. After abrupt release of this occlusion, at left ventricular end diastolic pressure less than 10 mmHg, end ejection lengths were longer than before the occlusion for both segments despite the same or lower end ejection pressures. When heart rate was not controlled the mean(SD) difference in end ejection length was 0.46(0.21) mm (n = 100). When heart rate was controlled by atrial pacing after autonomic blockade the difference was 0.37(0.11) mm (n = 80). In contrast, at left ventricular end diastolic pressure greater than 10 mmHg there was no significant difference between end ejection lengths before and after release of the aortic occlusion. Gradual release of the aortic occlusion over 4-5 beats produced clockwise hysteresis of the left ventricular end ejection pressure-length relation when left ventricular end diastolic pressure was less than 10 mmHg. No hysteresis occurred when left ventricular end diastolic pressure was greater than 10 mmHg. Hysteresis of the end systolic pressure-dimension relation was also seen when major and minor axis dimensions of the left ventricular were measured.(ABSTRACT TRUNCATED AT 250 WORDS)