Recurrence After Atrial Fibrillation Ablation and Investigational Biomarkers of Cardiac Remodeling.

BACKGROUND: Recurrence after atrial fibrillation (AF) ablation remains common. We evaluated the association between recurrence and levels of biomarkers of cardiac remodeling, and their ability to improve recurrence prediction when added to a clinical prediction model. METHODS AND RESULTS: Blood samples collected before de novo catheter ablation were analyzed. Levels of bone morphogenetic protein-10, angiopoietin-2, fibroblast growth factor-23, insulin-like growth factor-binding protein-7, myosin-binding protein C3, growth differentiation factor-15, interleukin-6, N-terminal pro-brain natriuretic peptide, and high-sensitivity troponin T were measured. Recurrence was defined as ≥30 seconds of an atrial arrhythmia 3 to 12 months postablation. Multivariable logistic regression was performed using biomarker levels along with clinical covariates: APPLE score (Age >65 years, Persistent AF, imPaired eGFR [<60 ml/min/1.73m2], LA diameter ≥43 mm, EF <50%; which includes age, left atrial diameter, left ventricular ejection fraction, persistent atrial fibrillation, and estimated glomerular filtration rate), preablation rhythm, sex, height, body mass index, presence of an implanted continuous monitor, year of ablation, and additional linear ablation. A total of 1873 participants were included. A multivariable logistic regression showed an association between recurrence and levels of angiopoietin-2 (odds ratio, 1.08 [95% CI, 1.02-1.15], P=0.007) and interleukin-6 (odds ratio, 1.02 [95% CI, 1.003-1.03]; P=0.02). The area under the receiver operating characteristic curve of a model that only contained clinical predictors was 0.711. The addition of any of the 9 studied biomarkers to the predictive model did not result in a statistically significant improvement in the area under the receiver operating characteristic curve. CONCLUSIONS: Higher angiopoietin-2 and interleukin-6 levels were associated with recurrence after atrial fibrillation ablation in multivariable modeling. However, the addition of biomarkers to a clinical prediction model did not significantly improve recurrence prediction.

Right Ventricular Dysfunction and Long-Term Risk of Sudden Cardiac Death in Patients With and Without Severe Left Ventricular Dysfunction.

BACKGROUND: Right ventricular systolic dysfunction (RVD) often coexists with various cardiopulmonary diseases. However, the association between RVD and risk of sudden cardiac death (SCD) has not been well studied. This study examined the risk of SCD associated with RVD in patients with heterogeneous underlying cardiac diseases. METHODS: The Mayo Clinic cardiac care unit database included 5463 consecutive patients with complete echocardiographic evaluation to assess right ventricular systolic function and RVD severity. Prospective surveillance follow-up was obtained for all patients. SCD was adjudicated when a malignant ventricular arrhythmia was documented as the primary rhythm leading to death. RESULTS: The prevalence of mild RVD and moderate-severe RVD was 14.9% and 17.1%, respectively. Patients with RVD were more likely to have a history of congestive heart failure, cardiac arrest, pulmonary disease, and lower baseline left ventricular ejection fraction compared with those with normal right ventricular systolic function. During a median follow-up of 14 months, the incidence of SCD was highest in patients with moderate-severe RVD (7.4% versus 4.4% in mild RVD versus 1.6% in normal right ventricular function; P<0.001). After adjustment for baseline characteristics, mild RVD (adjusted hazard ratio, 1.57; P=0.046) and moderate-severe RVD (adjusted hazard ratio, 1.91; P=0.006) were independently associated with an increased risk of SCD. Moderate-severe RVD remained an independent predictor of SCD for patients with left ventricular ejection fraction >35% without or with preexisting implantable cardioverter-defibrillator (adjusted hazard ratio, 4.12; P=0.003 and adjusted hazard ratio, 5.04; P<0.001, respectively). CONCLUSIONS: Presence of RVD in patients with a history of preexisting cardiac disease is an independent predictor of SCD irrespective of left ventricular ejection fraction.

A systematic analysis of UK cancer research funding by gender of primary investigator.

OBJECTIVES: To categorically describe cancer research funding in the UK by gender of primary investigator (PIs). DESIGN: Systematic analysis of all open-access data. METHODS: Data about public and philanthropic cancer research funding awarded to UK institutions between 2000 and 2013 were obtained from several sources. Fold differences were used to compare total investment, award number, mean and median award value between male and female PIs. Mann-Whitney U tests were performed to determine statistically significant associations between PI gender and median grant value. RESULTS: Of the studies included in our analysis, 2890 (69%) grants with a total value of £1.82 billion (78%) were awarded to male PIs compared with 1296 (31%) grants with a total value of £512 million (22%) awarded to female PIs. Male PIs received 1.3 times the median award value of their female counterparts (P<0.001). These apparent absolute and relative differences largely persisted regardless of subanalyses. CONCLUSIONS: We demonstrate substantial differences in cancer research investment awarded by gender. Female PIs clearly and consistently receive less funding than their male counterparts in terms of total investment, the number of funded awards, mean funding awarded and median funding awarded.

Investments in cancer research awarded to UK institutions and the global burden of cancer 2000-2013: a systematic analysis.

OBJECTIVES: To systematically categorise cancer research investment awarded to United Kingdom (UK) institutions in the period 2000-2013 and to estimate research investment relative to disease burden as measured by mortality, disability-adjusted life years (DALYs) and years lived with disability (YLDs). DESIGN: Systematic analysis of all open-access data. SETTING AND PARTICIPANTS: Public and philanthropic funding to all UK cancer research institutions, 2000-2013. MAIN OUTCOME MEASURES: Number and financial value of cancer research investments reported in 2013 UK pounds (UK£). Mortality, DALYs and YLDs data were acquired from the Global Burden of Disease Study. A compound metric was adapted to estimate research investment relative to disease burden as measured by mortality, DALYs and YLDs. RESULTS: We identified 4299 funded studies with a total research investment of £2.4 billion. The highest fundings by anatomical sites were haematological, breast, prostate, colorectal and ovarian cancers. Relative to disease burden as determined by a compound metric combining mortality, DALYs and YLDs, gender-specific cancers were found to be highest funded-the five sites that received the most funding were prostate, ovarian, breast, mesothelioma and testicular cancer; the least well-funded sites were liver, thyroid, lung, upper gastrointestinal (GI) and bladder. Preclinical science accounted for 66.2% of award numbers and 62.2% of all funding. The top five areas of primary research focus by funding were pathogenesis, drug therapy, diagnostic, screening and monitoring, women's health and immunology. The largest individual funder was the Medical Research Council. In combination, the five lowest funded site-specific cancers relative to disease burden account for 47.9%, 44.3% and 20.4% of worldwide cancer mortality, DALYs and YLDs. CONCLUSIONS: Research funding for cancer is not allocated according to relative disease burden. These findings are in line with earlier published studies. Funding agencies and industry should openly document their research investments to improve better targeting of research investment.

The influence of volume and experience on individual surgical performance: a systematic review.

OBJECTIVE: To systematically review studies evaluating the influence of surgical experience on individual performance. BACKGROUND: Experience, measured in case volume or years of practice, is recognized as a key driver of individual surgical performance, giving rise to a learning curve. However, this topic has not been reviewed at the cross-specialty level. METHODS: MEDLINE, EMBASE, PsycINFO, AMED, and the Cochrane Database of Systematic Reviews were searched (from inception to February 2013). Two reviewers independently reviewed citations using predetermined inclusion and exclusion criteria. Ninety-one data points per study were extracted. RESULTS: The search strategy yielded 6950 citations. Fifty-seven studies were eligible, including 1,061,913 cases and 35 procedure types, performed by 17,912 surgeons. Forty-five studies monitored case volume, and 6 studies measured experience as both case volume and years of practice. Of these 51 studies, 44 found that increased case volume was associated with significantly improved health outcomes. Several studies noted a plateau phase or maturation in the surgical learning curve. Acquisition of this phase was procedure specific and outcome specific, ranging from 25 to 750 procedures. Twelve studies assessed the impact of years of surgical practice, 11 of which found that increased years of experience was associated with significantly improved health outcomes. Two studies noted a plateau phase, where increases in years of experience were no longer associated with improvements in operative outcomes. Three studies identified performance deterioration after the plateau phase. CONCLUSIONS: Increasing surgical case volume and years of practice are associated with improved performance, in a procedure-specific manner. Performance may deteriorate toward the end of a surgeon's career.