Abstract P351: Ethnic Differences in the Risk Estimates of Novel Biomarkers for Future Cardiovascular Outcomes

Background: Elevated inflammatory markers, haemostatic factors as well as homocysteine predict cardiovascular disease (CVD) events and mortality. Although racial/ethnic disparities in CVD risk factors and outcomes exist, comparative data on the predictive utility of novel biomarkers for future CVD events in US ethnic groups is limited.

Methods: The study comprised 6814 asymptomatic men and women (52.85%), aged 45-84 yrs without prior cardiovascular disease, enrolled in the Multi-Ethnic Study of Atherosclerosis [MESA] obtained from NHLBI Data repository. 6270 asymptomatic men and women [1384 Hispanics, 2409 Caucasians, 753 Chinese and 1724 African Americans] with a host of novel biomarkers drawn were considered for this analysis. The CVD events were defined as ALL CVD events and HARD CVD events per MESA protocol (see Table).

Results: A total of 302 all CVD events and 203 hard CVD events were identified during a mean follow up of 4.6 years. We observed significant ethnic differences in the prognostic utility of novel biomarkers for cardiovascular risk assessment, in a large multi-ethnic population of US adults free of clinical cardiovascular disease. While homocysteine emerged as a robust biomarker across racial cohorts, most other biomarkers analyzed predominantly predicted events in Caucasians (see Table).

Conclusion: These findings raise serious concern about the prognostic potential or generalizability of risk stratification tools across racial subsets and underscore the need for further ethnicity-specific research in this area.

Abstract P185: Metabolic Syndrome and Cardiovascular Risk - A Comparative Analysis of Waist-Cricumference and Waist-Height-Ratio for Predictive Accuracy

Introduction: Metabolic syndrome (MS) is an adverse predictor of cardiovascular outcomes. Recently, waist height ratio (WHtR) is shown to correlate better with future cardiovascular risk factors than other anthropometric measures. We sought to determine whether replacing waist circumference (WC) with WHtR in metabolic syndrome diagnostic criteria per National Cholesterol Education Program (NCEP) guidelines improves predictive accuracy for future cardiovascular disease (CVD) events.

Methods: The study cohort consisted of prospectively evaluated 6,702 healthy adults aged 45-84 years enrolled in the Multi-Ethnic Study of Atherosclerosis [MESA] study [Age-: 62±10 years, 47% males, 1473 Hispanics, 2575 Caucasians, 799 Chinese and 1855 African Americans]. Metabolic syndrome (MSwc), at baseline, was defined by NCEP guidelines (n=2,208). Metabolic syndrome (MSwhtr) was redefined using WHtR (≥ 0.5 in both male and females) in place of WC, keeping rest of the components constant as recommended by NCEP (n=2,590). CVD events were defined as All CVD (CVDa) per MESA protocol (See Table ). Unadjusted and adjusted Cox-proportional hazard analysis was performed. Harrell's C-statistics were calculated for the most adjusted models.

Results: Total of 319 CVDa events [n=171 (7.44%) in MSwc group and n=190 (7.34%) in MSwhtr group] were identified during a mean follow up of 4.6 years. Results are displayed in the table .

Conclusion: Predictive accuracy of MS re-defined with WHtR and MS defined with WC per NCEP criteria is comparable.

Comparison of mortality and morbidity in patients with atrial fibrillation and heart failure with preserved versus decreased left ventricular ejection fraction

Almost 50% of patients with congestive heart failure (HF) have preserved ejection fraction (PEF). Data on the effect of HF-PEF on atrial fibrillation outcomes are lacking. We assessed the prognostic significance of HF-PEF in an atrial fibrillation population compared to a systolic heart failure (SHF) population. A post hoc analysis of the National Heart, Lung, and Blood Institute-limited access data set of the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial was carried out. The patients with a history of congestive HF and a preserved ejection fraction (EF >50%) were classified as having HF-PEF (n = 320). The patients with congestive HF and a qualitatively depressed EF (EF <50%) were classified as having SHF (n = 402). Cox proportional hazards analysis was performed. The mean follow-up duration was 1,181 ± 534 days/patient. The patients with HF-PEF had lower all-cause mortality (hazard ratio [HR] 0.62, 95% confidence interval [CI] 0.46 to 0.85, p = 0.003) and cardiovascular mortality (HR 0.56, 95% CI 0.38 to 0.84, p = 0.006), with a possible decreased arrhythmic end point (HR 0.39, 95% CI 0.16 to 1.006, p = 0.052) than did the patients with SHF. No differences were observed for ischemic stroke (HR 1.08, 95% CI 0.48 to 2.39, p = 0.86), rehospitalization (HR 0.89, 95% CI 0.75 to 1.07, p = 0.24), or progression to New York Heart Association class III-IV (odds ratio 0.80, 95% CI 0.42 to 1.54, p = 0.522). In conclusion, although patients with HF-PEF have better mortality outcomes than those with SHF, the morbidity appears to be similar.

Abstract P125: Correlation of Inflammatory Marker Burden with Progressive Increase in Short-Term Risk of Cardiovascular Disease

Background: Newer inflammatory markers of atherosclerosis have been shown to correlate well with cardiac risk profiling.

Methods: Multi-Ethnic study of Atherosclerosis (MESA) is a population based study (n=6814) of varying ethnicities, aged 44-84 years, free from clinical cardiovascular disease (CVD). We did a post-hoc analysis of the NHLBI Limited Access Dataset of MESA subjects between 44-50 years(n=1076), and stratified them into 3 risk groups- low 10-year (<10%)/low lifetime (<39%) risk, low 10-year (<10%)/high lifetime risk (>39%), and high 10-year risk (>10%) or diagnosed diabetes mellitus. C - reactive protein (CRP), fibrinogen, Interleukin 6 (Il-6) and plasmin-antiplasmin complex (PAC) levels were analyzed across the 3 groups. Further each quartile of a marker was assigned 1 point and a Mean inflammatory score was computed by adding total points for each patient in the risk groups. Age, sex and race adjusted regression co-efficients were estimated.

Results: Mean age of the study group was 47±1.7 yrs, CRP-3.3±4.9 mg/L, IL-6-1.4±1.1 pg/ml, fibrinogen-324±69. Mean levels of CRP, fibrinogen, Il-6, PAC and mean inflammatory score increased progressively across the 3 risk groups. Adjusted regression co-efficients also demonstrated linear relationship with increasing risk hierarchy (Table 1).

Conclusions: Burden of inflammatory markers increases progressively across risk groups- being the highest in those with high short term risk of cardiovascular disease.

The efficacy of sotalol in preventing postoperative atrial fibrillation: a meta-analysis

OBJECTIVE

Supraventricular tachyarrhythmias including atrial fibrillation are common and troubling complications after cardiac surgery, and thus considerable interest in pharmacologic prophylaxis has developed. The aim of this study was to evaluate the efficacy of sotalol in the prevention of postoperative supraventricular tachyarrhythmias.

METHODS

Standard methods of meta-analysis were used. Randomized clinical trials published in English language were eligible for the meta-analysis.

RESULTS

A systematic review revealed 15 eligible publications that provided 20 comparisons of sotalol with a control group. The incidence and relative risk (RR) with 95% confidence interval (CI) of developing postoperative supraventricular tachyarrhythmias while taking sotalol were sotalol (n=489) versus placebo (n=499): 22.5% versus 41.5%, RR=0.55 (CI, 0.454-0.667, P<.001); sotalol (n=304) versus no treatment (n=311): 12% versus 39%, RR=0.329 (CI, 0.236-0.459, P<.001); sotalol (n=488) versus beta-blocker (n=555): 14% versus 23%, RR=0.644 (CI, 0.495-0.838, P<.001); sotalol (n=139) versus amiodarone (n=146): no significant differences in supraventricular tachyarrhythmia prevention; and sotalol (n=51) versus magnesium (n=54): no significant differences in supraventricular tachyarrhythmia prevention. Initiating sotalol orally or intravenously had no significant effect on efficacy. Initiating sotalol after surgery showed a trend toward less adverse events (before: RR=1.700 [CI, 0.903-3.200] and after: RR=0.767 [CI, 0.391-1.505]).

CONCLUSION

Sotalol is more effective in the prevention of supraventricular tachyarrhythmia than placebo or beta-blockers. Initiating sotalol before cardiac surgery has no advantage compared with initiating sotalol shortly after surgery. Starting sotalol intravenously after surgery may be a more reliable method than administering via a nasogastric tube or delaying treatment until the patient can take oral medication.

Outcomes and Risk Prediction Model for Peripheral Arterial Disease in Patients with Stable Coronary Artery Disease

We used the National Heart, Lung, and Blood Institute Limited Access Dataset of Prevention of Events with Angiotensin-Converting Enzyme Inhibition (PEACE) Trial (n = 8290) which included patients with stable coronary artery disease (CAD) and preserved ejection fraction (>40%). We identified risk factors for the development of critical peripheral arterial disease (PAD; those needing angioplasty, bypass grafting, or aneurysm repair) and formulated a risk score by multivariate analyses. A total of 220 patients (2.8%) developed critical PAD over a mean follow-up of 4.7 years. Significant predictors of critical PAD were history of intermittent claudication, smoking, hypertension (HTN), coronary-artery bypass grafting (CABG), diabetes, age, serum cholesterol, and body mass index (BMI). Incident critical PAD was associated with increased composite outcome of cardiovascular death, myocardial infarction, percutaneous transluminal coronary angioplasty, or CABG (hazard ratio 1.82, 95% CI 1.50-2.22, P < .001). Risk assessment using our score may identify CAD patients at risk for critical PAD events.

Predictive factor and kappa angle analysis for visual satisfactions in patients with multifocal IOL implantation

PURPOSE

To evaluate the visual acuity and quality-related satisfaction of patients implanted with a refractive design multifocal intraocular lens (IOL), and evaluate the factors predicting it including angle kappa.

SETTING

Dr Agarwal's Eye Hospital and Eye Research Centre, Chennai.

METHODS

In this prospective trial, 50 eyes of 44 consecutive patients were included. All patients underwent phacoemulsification with multifocal IOL implantation (Rezoom IOL, Abbott Medical Optics). The preoperative and postoperative assessment included slit lamp biomicroscopy, uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA) and kappa angle assessment. At 1 year, 37 patients (43 eyes), who finished follow-up, were asked to rate their symptoms on a graded questionnaire (0-5 for five queries).

RESULTS

The decimal scores for UCVA and BCVA were 0.38±0.21 and 0.47±0.17 (preoperative), and 0.75±0.22 and 0.99±0.11 (postoperative), respectively. Symptom scores were haloes 0.98±1.7, glare 0.69±1.48, blurred distance 1.0±1.7, intermediate 1.34±1.6, near 1.06±1.8. On regression analysis haloes depended on angle kappa and distance UCVA (R (2)=0.26, P=0.029), and glare on angle kappa (R (2)=0.26, P=0.033). Poor satisfactions with distance, intermediate, and near vision were linked with distance UCVA (R (2)=0.17, P=2.3 × 10(-4)), distance UCVA (R (2)=0.1, P=0.04), and near UCVA (R (2)=0.12, P=0.03), respectively. The strongest predictor, however, for overall visual discomfort was distance UCVA (R (2)=0.1, P=0.04).

CONCLUSIONS

Our study suggests that there may be a role of misalignment between the visual and pupillary axis (angle kappa) in the occurrence of photic phenomenon after refractive multifocal IOL implantation.

Outcomes following a limited approach to radiotherapy in rectal cancer

BACKGROUND

Variation in the use of neoadjuvant and adjuvant radiotherapy for rectal cancer suggests an opportunity to avoid it in all but patients at highest risk of local recurrence.

METHODS

Between 1 July 1999 and 1 February 2006, patients with primary rectal cancer were treated by a single surgeon operating at McMaster University, Hamilton, Ontario, Canada. Digital rectal examination and pelvic computed tomography were used to determine whether the mesorectal margin was threatened by tumour and thus whether preoperative radiotherapy would be needed. The study outcome was local tumour recurrence.

RESULTS

Forty-six (48 per cent) of 96 patients received preoperative radiation therapy. The median follow-up was 4·2 years. Tumours were fixed or tethered in 31 (67 per cent) of the 46 irradiated patients. In contrast, no tumour was fixed in unirradiated patients and only ten (20 per cent) of the 50 tumours were tethered. The proportion of patients with stage I or II tumours based on final pathology was similar: 61 per cent (28 of 46) and 56 per cent (28 of 50) in irradiated and unirradiated groups respectively (P = 0·287). There were four (9 per cent) and two (4 per cent) local recurrences among irradiated and unirradiated patients respectively (P = 0·422).

CONCLUSION

Limiting preoperative radiotherapy in rectal cancer to patients with a threatened circumferential margin does not compromise patient outcome.

Monitoring of water quality from roof runoff: Interpretation using multivariate analysis

The quality of harvested rainwater used for toilet flushing in a private house in the south-west of France was assessed over a one-year period. Temperature, pH, conductivity, colour, turbidity, anions, cations, alkalinity, total hardness and total organic carbon were screened using standard analytical techniques. Total flora at 22 °C and 36 °C, total coliforms, Escherichia coli and enterococci were analysed. Overall, the collected rainwater had good physicochemical quality but did not meet the requirements for drinking water. The stored rainwater is characterised by low conductivity, hardness and alkalinity compared to mains water. Three widely used bacterial indicators - total coliforms, E. coli and enterococci - were detected in the majority of samples, indicating microbiological contamination of the water. To elucidate factors affecting the rainwater composition, principal component analysis and cluster analysis were applied to the complete data set of 50 observations. Chemical and microbiological parameters fluctuated during the course of the study, with the highest levels of microbiological contamination observed in roof runoffs collected during the summer. E. coli and enterococci occurred simultaneously, and their presence was linked to precipitation. Runoff quality is also unpredictable because it is sensitive to the weather. Cluster analysis differentiated three clusters: ionic composition, parameters linked with the microbiological load and indicators of faecal contamination. In future surveys, parameters from these three groups will be simultaneously monitored to more accurately characterise roof-collected rainwater.

Clinical applications of magnets on cardiac rhythm management devices

The growing indications for permanent pacemaker and implantable cardioverter defibrillator (ICD) implantation have increased the number of patients with these cardiac rhythm management devices (CRMDs). Cardiac rhythm management devices occasionally perform inappropriately in response to electromagnetic interference (e.g. surgical electrocautery) or lead noise over-sensing (e.g. lead fracture). Temporary reprogramming of the CRMDs using device programmers can prevent these untoward device responses. However, these programmers are device manufacturer specific and require technically qualified personnel to operate. This could cause delayed patient care and increased use of resources in certain clinical situations. Alternatively, clinical magnets, when appropriately positioned over the device site, can change the pacing to an asynchronous mode in pacemakers and suspend tachycardia therapies in ICDs. Although readily available, clinical magnets have not been widely used for this purpose, perhaps due to the unfamiliarity with the variable responses of CRMDs to magnet application. This article provides a comprehensive overview of the current literature on the mechanism of action and the specific responses of various CRMDs to clinical magnets.