Mechanisms, predictors and clinical markers of dysphagia in cardiac surgical patients - Project Summary Dysphagia (swallowing impairment) is a common complication of cardiac surgical procedures, leading to malnutrition, dehydration, aspiration pneumonia, reintubation, increased health care utilization, length of hospitalization, and economic burden. Although preventable, dysphagia-related aspiration pneumonia is a major cause of mortality. Early detection and accurate monitoring of dysphagia are therefore important to facilitate timely interventions to mitigate developing sequelae. Currently, clinical care of dysphagia is hindered by fundamental gaps in knowledge, including 1) contributing risk factors of dysphagia are unknown, prohibiting the use of triaged personalized care pathways; 2) no validated tools to accurately detect and monitor dysphagia in the cardiac intensive care unit exist; and 3) governing mechanisms of swallowing impairment and recovery of function are unknown, impeding the development of mechanistically guided therapeutics and optimization of salient postoperative evaluation time points. Our three specific aims target these knowledge gaps with the broad goal to shift care toward a proactive, multifaceted, and data-driven perioperative Model of Swallowing Integrated Care (MOSAIC). To this end, we will enroll 360 cardiac surgical patients over a four-year period and identify 1) independent risk factors for dysphagia, 2) sensitive clinical markers of swallowing impairment, and 3) governing physiologic mechanisms of unsafe and inefficient swallowing throughout the acute, sub-acute, and long-term postoperative period. Enrolled participants will undergo a preoperative Fiberoptic Endoscopic Evaluation of Swallowing (FEES) to screen out patients with pre-existing dysphagia. Candidate predictor variables will be systematically collected throughout the perioperative time course. Following surgery and within 48 hours of extubation, a simultaneous videofluoroscopy and FEES (VF-FEES) will be performed as well as a battery of simple bedside clinical tests. Detailed blinded analyses will be performed using validated metrics of swallowing safety, efficiency, timing and kinematics to examine acute-phase swallowing function and associated physiologic mechanisms of unsafe or inefficient deglutition. Patients with acute postoperative phase dysphagia will be re-examined at one- and six-months to determine sub-acute and long-term dysphagia trajectories and governing mechanisms of impairment and recovery. Multivariable modeling of dysphagia risk factors will produce a practical dysphagia risk stratification tool to enable accurate forecasting and personalized triaged postoperative care pathways. An accompanying open-access electronic application will be developed to provide seamless clinical adoption and a data-driven clinical decision making tool. The discriminant ability of clinical markers will be determined, and a practical bedside dysphagia screening tool will be validated to enable accurate detection and monitoring of dysphagia in the cardiac intensive care unit. Outcomes will drive future targeted therapeutic and preventative strategies and enhance personalized health care models to ultimately improve patient outcomes.