Benjamin D. Pollock M.S.P.H.

Filardo, G., R. J. Damiano, Jr., G. Ailawadi, V. H. Thourani, B. D. Pollock, D. M. Sass, T. K. Phan, H. Nguyen and B. da Graca (2018). “Epidemiology of new-onset atrial fibrillation following coronary artery bypass graft surgery.” Heart 104(12): 985-992.

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OBJECTIVES: Postoperative atrial fibrillation (AF) following coronary artery bypass graft surgery (CABG) is significantly associated with reduced survival, but poor characterisation and inconsistent definitions present barriers to developing effective prophylaxis and management. We sought to address this knowledge gap. METHODS: From 2002 to 2010, 11 239 consecutive patients without AF underwent isolated CABG at five sites. Clinical data collected for the Society of Thoracic Surgeons (STS) Database were augmented with details on AF detected via continuous in-hospital ECG/telemetry monitoring to assess new-onset post-CABG AF (adjusted for STS risk of mortality); time to first AF; durations of first and longest AF episodes; total in-hospital time in AF; number of in-hospital AF episodes; operative mortality; stroke; discharge in AF; and length of stay (LOS). RESULTS: Unadjusted incidence of new-onset post-CABG AF was 29.5%. Risk-adjusted incidence was 33.1% and varied little over time (P=0.139). Among 3312 patients with post-CABG AF, adjusted median time to first AF was 52 (IQR: 48-55) hours; mean (SD) duration of first and longest events were 7.2 (5.3,9.1) and 13.1 (10.4,15.9) hours, respectively, and adjusted median total time in AF was 22 (IQR: 18-26) hours. Adjusted rates of operative mortality, stroke and discharge in AF did not vary significantly over time (P=0.156, P=0.965 and P=0.347, respectively). LOS varied (P=0.035), but in no discernible pattern. CONCLUSIONS: Each year, ~800 000 people undergo CABG worldwide; >264 000 will develop post-CABG AF. Onset is typically 2-3 days post-CABG and episodes last, on average, several hours. Effective prophylaxis and management is urgently needed to reduce associated risks of adverse outcomes.

Bertisch, S. M., B. D. Pollock, M. A. Mittleman, D. J. Buysse, L. A. Bazzano, D. J. Gottlieb and S. Redline (2018). “Insomnia with Objective Short Sleep Duration and Risk of Incident Cardiovascular Disease and All-Cause Mortality: Sleep Heart Health Study.” Sleep. Mar 7. [Epub ahead of print].

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Study Objectives: To quantify the association between insomnia/poor sleep with objective short sleep and incident cardiovascular disease (CVD) and mortality in the general population. Methods: We conducted a time-to-event analysis of Sleep Heart Health Study data. Questionnaires and at-home polysomnography were performed between 1994 -1998. Participants were followed for a median 11.4 years (Q1-Q3, 8.8-12.4 years) until death or last contact. The primary exposure was insomnia or poor sleep with short sleep defined as: difficulty falling asleep, difficulty returning to sleep, early morning awakenings, or sleeping pill use, 16-30 nights/month; and total sleep <6 hours on polysomnography (PSG). We used proportional hazards models to estimate the association between insomnia/poor sleep with short sleep and CVD, as well as all-cause mortality. Results: Among 4,994 participants (mean age 64.0 +/- 11.1 years), 14.1% reported insomnia or poor sleep, of which 50.3% slept <6 hours. Among 4,437 CVD-free participants at baseline, we observed 818 incident CVD events. After propensity-adjustment, there was a 29% higher risk of incident CVD in the insomnia/poor sleep with short sleep group compared with the reference group (HR, 1.29, 95% CI, 1.00, 1.66), but neither the insomnia/poor sleep only nor short sleep only groups were associated with higher incident CVD. Insomnia/poor sleep with objective short sleep was not significantly associated with all-cause mortality (HR, 1.07, 95% CI, 0.86, 1.33). Conclusions: Insomnia/poor sleep with PSG-short sleep was associated with higher risk of incident CVD. Future studies should evaluate the impact of interventions to improve insomnia with PSG-short sleep on CVD.

Pollock, B. D., E. W. Harville, K. T. Mills, W. Tang, W. Chen and L. A. Bazzano (2018). “Cardiovascular Risk and the American Dream: Life Course Observations From the BHS (Bogalusa Heart Study).” J Am Heart Assoc 7(3).

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BACKGROUND: Economic literature shows that a child’s future earnings are predictably influenced by parental income, providing an index of “socioeconomic mobility,” or the ability of a person to move towards a higher socioeconomic status from childhood to adulthood. We adapted this economic paradigm to examine cardiovascular risk mobility (CRM), or whether there is life course mobility in relative cardiovascular risk. METHODS AND RESULTS: Participants from the BHS (Bogalusa Heart Study) with 1 childhood and 1 adult visit from 1973 to 2016 (n=7624) were considered. We defined population-level CRM as the rank-rank slope (beta) from the regression of adult cardiovascular disease (CVD) risk percentile ranking onto childhood CVD risk percentile ranking (beta=0 represents complete mobility; beta=1 represents no mobility). After defining and measuring relative CRM, we assessed its correlation with absolute cardiovascular health using the American Heart Association’s Ideal Cardiovascular Health metrics. Overall, there was substantial mobility, with black participants having marginally better CRM than whites (betablack=0.10 [95% confidence interval, 0.05-0.15]; betawhite=0.18 [95% confidence interval, 0.14-0.22]; P=0.01). Having high relative CVD risk at an earlier age significantly reduced CRM (betaagexslope=-0.02; 95% confidence interval, -0.03 to -0.01; P<0.001). Relative CRM was strongly correlated with life course changes in Ideal Cardiovascular Health sum (r=0.62; 95% confidence interval, 0.60-0.65). CONCLUSIONS: Results from this novel application of an economic mobility index to cardiovascular epidemiology indicated substantial CRM, supporting the paradigm that life course CVD risk is highly modifiable. High CRM implies that the children with the best relative CVD profiles may only maintain a slim advantage over their peers into adulthood.

Arsalan, M., W. K. Kim, A. Van Linden, C. Liebetrau, B. D. Pollock, G. Filardo, M. Renker, H. Mollmann, M. Doss, U. Fischer-Rasokat, A. Skwara, C. W. Hamm and T. Walther (2018). “Predictors and outcome of conversion to cardiac surgery during transcatheter aortic valve implantation.” Eur J Cardiothorac Surg. Mar 1. [Epub ahead of print].

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OBJECTIVES: Due to increasing clinical experience with transcatheter aortic valve implantation (TAVI) procedures, sophisticated imaging and advanced device technology, TAVI complication rates are low; however, patients requiring conversion to surgery are confronted with an increased mortality risk. In this retrospective study, we evaluated the predictors for conversion and the outcomes of these patients. METHODS: We analysed the records of all patients undergoing TAVI in our centre from 2011 to 2016 and focused on cases that required conversion to sternotomy. We investigated reasons and risk factors for conversion as well as 30-day and 1-year outcomes. RESULTS: During the study period, 32 (2.1%) of 1775 patients undergoing TAVI required immediate conversion to sternotomy. Annular rupture (5 of 32; 16%), device embolization (9 of 32; 28%) and pericardial tamponade (15 of 32; 47%) were the most common reasons for conversion. Usage of a self-expandable valve showed to be the only predictor for conversion (odds ratio 0.38, 95% confidence interval 0.16-0.90; P = 0.03). Survival at 30 days and 1 year was 56% and 41%, respectively. Patients who survived 30 days after conversion showed higher preoperative ejection fraction, shorter duration of surgery and shorter perfusion time. CONCLUSIONS: In this high-volume, single-centre experience, conversion to sternotomy during TAVI occurred in about 2%, with annular rupture, device embolization and pericardial tamponade being the most common causes. Complications requiring conversion showed to be unpredictable. However, in view of these life-threatening complications, the 30-day survival rate exceeding 50% emphasizes the importance of an experienced and well-attuned heart team providing immediate access to surgical bailout procedures.

Pollock, B. D., G. Filardo, B. da Graca, T. K. Phan, G. Ailawadi, V. Thourani, R. J. Damiano, Jr. and J. R. Edgerton (2018). “Predicting New-Onset Post-Coronary Artery Bypass Graft Atrial Fibrillation With Existing Risk Scores.” Ann Thorac Surg 105(1): 115-121.

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BACKGROUND: New-onset atrial fibrillation (AF) after coronary artery bypass graft (CABG) operation is associated with poorer survival. Blanket prophylaxis efforts have not appreciably decreased incidence, making targeted prevention for high-risk patients desirable. We compared predictive abilities of existing scores developed/used to predict adverse CABG outcomes (Society of Thoracic Surgeons’ [STS] risk of mortality) or AF not associated with cardiac operation (the Cohorts for Heart and Aging Research in Genomic Epidemiology [CHARGE]-AF score, the CHA2DS2-VASc score), and a risk model for predicting postoperative AF following cardiac operations (POAF score), with age (the most consistently identified post-CABG AF risk factor). METHODS: Data submitted to the STS Adult Cardiac Surgery Database were used to assess new-onset AF in 8,976 consecutive patients without preoperative AF undergoing isolated CABG from 2004 to 2010 at five participating centers. Five logistic regression models (for CHA2DS2-VASc score, CHARGE-AF score, POAF score, STS risk score, and age, respectively, all modeled with restricted cubic splines) with a random effect for site were fitted to predict post-CABG AF. Estimates were used to compute and compare receiver operating characteristic (ROC) areas. RESULTS: New-onset AF occurred in 2,141 patients (23.9%). The ROC area was greatest for CHARGE-AF (0.68, 95% confidence interval [CI]: 0.67-0.69), followed by age (0.66, 95% CI: 0.65-0.68), POAF score (0.65, 95% CI: 0.64-0.66), CHA2DS2-VASc (0.59, 95% CI: 0.58 to 0.60), and STS risk of mortality (0.58, 95% CI: 0.56-0.59). CHARGE-AF was significantly more predictive than age (p < 0.0001); the other scores were significantly less predictive (p < 0.0001). CONCLUSIONS: Only CHARGE-AF performed better than age alone. Its performance was moderate and comparable with published risk models specifically targeted at new-onset post-isolated CABG AF. Future research should continue to focus on developing better predictive models.