Risk Prediction in Older Adults After Acute Myocardial Infarction: the Is Lver-Ami Study David William Goldstein
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Yale University EliScholar – A Digital Platform for Scholarly Publishing at Yale Yale Medicine Thesis Digital Library School of Medicine January 2018 Risk Prediction In Older Adults After Acute Myocardial Infarction: The iS lver-Ami Study David William Goldstein Follow this and additional works at: https://elischolar.library.yale.edu/ymtdl Recommended Citation Goldstein, David William, "Risk Prediction In Older Adults After Acute Myocardial Infarction: The iS lver-Ami Study" (2018). Yale Medicine Thesis Digital Library. 3399. https://elischolar.library.yale.edu/ymtdl/3399 This Open Access Thesis is brought to you for free and open access by the School of Medicine at EliScholar – A Digital Platform for Scholarly Publishing at Yale. It has been accepted for inclusion in Yale Medicine Thesis Digital Library by an authorized administrator of EliScholar – A Digital Platform for Scholarly Publishing at Yale. For more information, please contact [email protected]. RISK PREDICTION IN OLDER ADULTS AFTER ACUTE MYOCARDIAL INFARCTION: THE SILVER-AMI STUDY A Thesis Submitted to the YAle University School of Medicine in Partial Fulfillment of the Requirements for the Degree of Doctor of Medicine by DAvid WilliAm Goldstein 2018 Table of Contents i. AbstrAct ii. Acknowledgments I. Introduction 1 a. Statement of Purpose 3 II. Methods of the SILVER-AMI study 4 III. ChApter 1: FActors AssociAted with fAlls in older Adults after acute myocardial infarction 8 a. Background 8 b. Methods 11 c. Results 15 d. Discussion 23 IV. ChApter 2: FActors AssociAted with non-utilization of cArdiAc rehAbilitAtion in older Adults After Acute myocardial infarction 29 a. BAckground 29 b. Methods 34 c. Results 36 d. Discussion 41 V. Conclusions 46 VI. References 49 VII. Appendix A: Accepted review mAnuscript for Current CArdiovAsculAr Risk Reviews 59 VIII. Appendix B: Accepted AbstrAct for AmericAn GeriAtrics Society conference presentAtion 62 AbstrAct: Older adults are at risk for functional decline after hospitalization for acute myocardial infarction (AMI). Our goal with this thesis is to explore two outcomes relevant to maintenance of physical function, falls and cardiac rehabilitation (CR) utilization in a cohort of adults over the age of 75 hospitalized with acute myocardial infarction. We aim to describe the risk of falls within six months of discharge and the rates of CR use, and to identify factors associated with these outcomes. Our project uses data from the SILVER-AMI study, a prospectively designed cohort study which enrolled 3000 patients over the age of 75 hospitalized with acute myocardial infarction and followed them for six months after discharge. Extensive baseline data was collected on demographics, clinical and psychosocial factors, and geriatric impairments. Outcome data on falls was collected at six months via medical record adjudication and survey, and on CR use by survey. 557 (21.6%) of 2584 participants reported at least one fall within six months of discharge. Independent predictors after logistic regression analysis included: impaired functional mobility (OR 1.5 [1.07-2.11]), recent fall history (OR 2.97 [2.37- 3.74]), longer length of stay (OR 1.04 [1.02-1.07] per day, visual impairment (OR 1.33 [1.08-1.64]), and weak grip strength (OR 1.28 [1.02-1.60]). 192 (6.4%) of 3006 participants were found to have a medically serious fall within six months of discharge. Independent predictors of medically serious falls after logistic regression analysis included: impaired functional mobility (OR 1.85 [1.11-3.09]), recent fall history (OR 1.73 [1.23-2.42]), longer length of stay (OR 1.03 [1.01-1.06] per day, living alone (OR 1.37 [1.00-1.87, p = 0.048]), and impairment in the bathing ADL (OR 1.74 [1.06-2.86]). 943 (39.5%) of 2387 participants reported participating in CR within six months of discharge. Independent predictors of CR use after logistic regression analysis included: older age (OR 0.97 [0.95-0.99] per year), non-white race (OR 0.69 [0.50-0.97]), having less than 12 years of education (OR 0.71 [0.59-0.85]), receiving percutaneous (OR 2.07 [1.66-2.57]) or surgical (OR 4.70 [3.32-6.67]) revascularization, cognitive impairment (OR 0.58 [0.43-0.78]), and living alone (OR 0.77 [0.64-0.93]). From these results, we conclude that falls and CR underutilization are important problems facing older adults after AMI. The comprehensive geriatric assessment performed in SILVER-AMI highlighted independent robust predictors of both functional outcomes. This indicates that there is a role for assessing geriatric impairments during an AMI hospitalization, as identifying patients at risk for poor functional outcomes can lead to steps toward improving their care. High fall risk could be a reason to avoid anticoagulant therapy. Identifying patients less likely to attend CR can allow development of interventions to close this gap in care. Acknowledgments: I would like to humbly thank my advisor, Sarwat Chaudhry, for her patience, generosity, and dedication to mentorship throughout this process. She is a role model for me as a researcher, clinician, and person. She has taught me the skills required to design a research question, manage a team, and follow a project through to completion, and she has left me the room to develop independence in those skills. She has been a remarkable resource since we first met, and I could not imagine a better mentor and advisor for me. As a result, I thank Mike Nanna for recommending her as a mentor. I would also like to thank my other formal and informal advisors, Ally Hajduk, Dan Forman, Patrick O’Connor, Dave Stitelman, and Arjun Venkatesh, as well as my former advisors, Joel Finkelstein and Kevin Sheth. They have all helped me grow immensely as a scientist, writer, and thinker over the years. I must also thank the Yale Office of student research and the NIH CTSA program for funding the research underlying this work, as well as the SILVER-AMI team, especially Mary Geda, Terry Murphy, and Xuemei Song, for their generosity in support of my projects. I joyfully thank my parents and family for their eternal love and support through my long educational journey. None of my accomplishments would be possible without them behind me. Finally, I thank my wife, Cate, for challenging me, supporting me, and providing me so much joy in my life. 1 I. INTRODUCTION: Demographic shifts in the United States have led to radical changes in the population’s healthcare needs and utilization. The number of older adults has grown rapidly, as has the incidence of cardiovascular disease in this group, particularly acute myocardial infarction. Over recent decades, a new field of medicine, geriatric cardiology, has blossomed to care for older adults with cardiovascular disease(1). These older patients differ from their younger counterparts in a number of dimensions, and their care requires a thoughtful understanding of their unique needs. Older adults’ increased burden of comorbid diseases and aging-specific impairments in cognition and physical function, combined with their limited physiologic reserve, mean that they are a group that is exceptionally vulnerable to poor outcomes after AMI. While older age itself is a known risk factor for unfavorable outcomes, this risk is not distributed evenly across the geriatric population. Older adults are extremely heterogeneous, and the various impairments and comorbidities exist to varying degrees that may or may not correspond with age. Not all older adults exhibit the aging phenotype, and their physiologic age may not always correspond with chronologic age. Despite the broad interest in better understanding the unique aspects of older adults that impact their cardiovascular care and outcome, few studies have utilized direct observation to develop new risk-prediction tools in this population, and most have relied on administrative datasets. Administrative studies, while useful, lack some of the granular data that may provide a richer understanding of the ways in which geriatric issues impact cardiac care and outcomes. The 2 Comprehensive Evaluation of Risk Factors in Older Patients with AMI (SILVER-AMI) is a recently completed study designed to address these issues and add new context to risk-prediction in older adults after acute MI. The study enrolled 3000 adults over 75 years old hospitalized with AMI throughout their hospitalization and followed each for 6 months after discharge. As a large, national study of patients hospitalized for AMI, one of the unique aspects of SILVER was its inclusion of a thorough geriatric assessment. This assessment includes gait speed, vision, hearing, cognition, and strength. Such geriatric impairments are not available in large administrative data sets, and while their importance in the field of geriatrics has been well established, neither their prevalence in post-AMI patients nor their significance for risk- prediction in that population is well understood. SILVER-AMI is primarily designed to test the associations of these geriatric-associated variables, along with a host of clinical, demographic, and psychosocial factors, with outcomes including readmission, mortality, and decline in health status. The study has generated far more information, and the sub-studies included in this thesis are focused on using the rich data from SILVER-AMI to investigate associations with outcomes that are uniquely important to patients and practitioners of geriatric cardiology. Older adults consistently identify maintaining physical function as a top priority(2), and while quality improvement efforts and evolving knowledge have made great strides in improving readmission and mortality after AMI, less attention has been paid to functional outcomes. This thesis utilizes the rich data of the SILVER-AMI study to discover risk factors for outcomes that are more relevant to maintenance of functional status. These outcomes include one adverse event, falls, 3 and one healthcare utilization outcome, cardiac rehabilitation (CR) use.