A modified intraventricular balloon method for functional assessment of hearts from donation after circulatory death.

Objective: Functional assessment of hearts during ex-vivo heart perfusion is not well-established. Conventional intraventricular balloon methods for large animals sacrifice the mitral valve. This study assessed the effectiveness of the modified intraventricular balloon method in comparison with other modalities used during working mode in juvenile pigs. Methods: Following asphyxia circulatory arrest, hearts were ischemic for 15 minutes and then reperfused on an ex-vivo device for 2 hours before switching to working mode. Left ventricular pressure was continuously measured during reperfusion by a saline-filled balloon fixated in the left atrium. Spearman Correlation Coefficients with linear regression lines with confidence intervals were analyzed. Results: Maximum dp/dt at 90 minutes of reperfusion and minimum dp/dt at 60 minutes of reperfusion showed a moderate positive correlation to that in working mode, respectively (Rs = 0.61, P = .04 and Rs = 0.60, P = .04). At 60 minutes of reperfusion, minimum dp/dt showed moderate positive correlation to tau (Rs = 0.52, P = .08). Myocardial oxygen consumption during reperfusion consistently decreased at least 30% compared to working mode (at 90 minutes as the highest during reperfusion, 3.3 ± 0.8; in working mode, 5.6 ± 1.4, mLO2/min/100 g, P < .001). Conclusions: Functional parameters of contractility and relaxation measured during reperfusion by the modified balloon method showed significant correlations to respective parameters in working mode. This mitral valve sparing technique can be used to predict viability and ventricular function in the early phase of ex-vivo heart perfusion without loading the heart during working mode.

Mitral valve surgery in patients with Marfan syndrome.

OBJECTIVE: To review the pathology of the mitral valve (MV) and long-term outcomes of surgery in patients with Marfan syndrome (MFS). PATIENTS AND METHODS: From 1988 through 2020, 60 patients with MFS had surgery to correct mitral regurgitation (MR): 19 had isolated MV surgery, 32 had combined MV and aortic root surgery, and 9 had MV surgery after aortic root surgery. Follow-up was complete for a median of 16.1 years. RESULTS: MV pathology was myxomatous degeneration in all patients and of advanced degree in 78.6% with bileaflet prolapse in 65.5%, mitral annulus disjunction in 57.5%, and mitral annulus calcification in 8.2% of patients. The MV was repaired in 47 patients and replaced in 13. Kaplan-Meier estimates of cumulative mortality at 20 years 21.3% for all patients, 6.7% after MV repair, and 57.8% after replacement (P < .001). MV reoperations were performed in 5 patients: 2 after repair and 3 after replacement. The cumulative incidence rate of reoperations on the MV was 3.8% at 10 years and 11.0% at 20 years in the entire cohort. Among 47 patients who had MV repair, moderate MR developed in 11 patients and severe in 2. Both patients with severe MR underwent MV reoperation. The cumulative incidence rate of recurrent moderate or severe MR after MV repair was 20.4% at 10 years, and 36.5% at 20 years. CONCLUSIONS: MV repair was associated with better survival than MV replacement, but recurrent MR after repair occurred in approximately one-third of the patients at 20 years after surgery.

The Effect of Using a Remote Patient Management Platform in Optimizing Guideline-Directed Medical Therapy in Heart Failure Patients: A Randomized Controlled Trial.

BACKGROUND: Guideline-directed medical therapy (GDMT) remains underutilized in patients with heart failure with reduced ejection fraction, leading to morbidity and mortality. OBJECTIVES: The Medly Titrate (Use of Telemonitoring to Facilitate Heart Failure Mediation Titration) study was an open-label, randomized controlled trial to determine whether remote medication titration for patients with heart failure with reduced ejection fraction was more effective than usual care (UC). METHODS: In this study, 108 patients were randomized to remote GDMT titration through the Medly heart failure program (n = 56) vs UC (n = 52). The primary outcome was the proportion of patients completing GDMT titration at 6 months. Secondary outcomes included the number of clinic visits and time required to achieve titration, patient health outcomes, and health care utilization, including urgent clinic/emergency department visits and hospitalization. RESULTS: At 6 months, GDMT titration was completed in 82.1% (95% CI: 71.2%-90.8%) of patients in the intervention arm vs 53.8% in UC (95% CI: 41.1%-67.7%; P = 0.001). Remote titration required fewer in-person (1.62 ± 1.09 vs 2.42 ± 1.65; P = 0.004) and virtual clinic visits (0.50 ± 1.08 vs 1.29 ± 1.86; P = 0.009) to complete titration. Median time to optimization was shorter with remote titration (3.42 months [Q1-Q3: 2.99-4.04 months] vs 5.47 months [Q1-Q3: 4.14-7.33 months]; P < 0.001). The number of urgent clinic/emergency department visits (incidence rate ratio of remote vs control groups: 0.90 [95% CI: 0.53-1.56]; P = 0.70) were similar between groups, with a reduction in all-cause hospitalization with remote titration (incidence rate ratio: 0.55 [95% CI: 0.31-0.97]; P = 0.042). CONCLUSIONS: Remote titration of GDMT in heart failure with reduced ejection fraction was effective, safe, feasible, and increased the proportion of patients achieving target doses, in a shorter period of time with no excess adverse events compared with UC. (Use of Telemonitoring to Facilitate Heart Failure Mediation Titration [Medly Titrate]; NCT04205513).

Cardiovascular Events After Aortic Root Repair in Patients With Marfan Syndrome.

BACKGROUND: The usefulness of aortic valve sparing operations to treat aortic root aneurysm in patients with Marfan syndrome (MS) remains controversial. OBJECTIVES: The purpose of this study was to evaluate the occurrence of cardiovascular events in patients with MS who have undergone valve-preserving aortic root replacement. METHODS: Patients with MS who had aortic valve sparing operations (reimplantation of the aortic valve or remodeling of the aortic root) from 1988 through 2019 were followed prospectively for a median of 14 years. Pertinent data from clinical, echocardiographic, computed tomography, and magnetic resonance images of the aorta were collected and analyzed. RESULTS: There were 189 patients whose mean age was 36 years, and 67% were men. Ten patients presented with acute type A dissection and 29 had mitral regurgitation. There were 52 patients at risk at 20 years. Mortality rate at 20 years was 21.5% (95% CI: 14.7%-30.8%); advancing age and preoperative aortic dissections were associated with increased risk of death by multivariable analysis. At 20 years, the cumulative incidence of moderate or severe aortic insufficiency was 14.5% (95% CI: 9.5%-22.0%), reoperation on the aortic valve was 7.5% (95% CI: 3.9%-14.7%), and new distal aortic dissections was 19.9% (95% CI: 13.9%-28.5%). Remodeling of aortic root was associated with greater risk of developing aortic insufficiency and aortic valve reoperation than reimplantation of the aortic valve. CONCLUSIONS: Aortic valve sparing operations provide stable aortic valve function and low rates of valve-related complications during the first 2 decades of follow-up but aortic dissections remain problematic in patients with MS.

Risk of Sudden Death in Patients With RASopathy Hypertrophic Cardiomyopathy.

BACKGROUND: Genetic defects in the RAS/mitogen-activated protein kinase pathway are an important cause of hypertrophic cardiomyopathy (RAS-HCM). Unlike primary HCM (P-HCM), the risk of sudden cardiac death (SCD) and long-term survival in RAS-HCM are poorly understood. OBJECTIVES: The study's objective was to compare transplant-free survival, incidence of SCD, and implantable cardioverter-defibrillator (ICD) use between RAS-HCM and P-HCM patients. METHODS: In an international, 21-center cohort study, we analyzed phenotype-positive pediatric RAS-HCM (n = 188) and P-HCM (n = 567) patients. The between-group differences in cumulative incidence of all outcomes from first evaluation were compared using Gray's tests, and age-related hazard of all-cause mortality was determined. RESULTS: RAS-HCM patients had a lower median age at diagnosis compared to P-HCM (0.9 years [IQR: 0.2-5.0 years] vs 9.8 years [IQR: 2.0-13.9 years], respectively) (P < 0.001). The 10-year cumulative incidence of SCD from first evaluation was not different between RAS-HCM and P-HCM (4.7% vs 4.2%, respectively; P = 0.59). The 10-year cumulative incidence of nonarrhythmic deaths or transplant was higher in RAS-HCM compared with P-HCM (11.0% vs 5.4%, respectively; P = 0.011). The 10-year cumulative incidence of ICD insertions, however, was 5-fold lower in RAS-HCM compared with P-HCM (6.9% vs 36.6%; P < 0.001). Nonarrhythmic deaths occurred primarily in infancy and SCD primarily in adolescence. CONCLUSIONS: RAS-HCM was associated with a higher incidence of nonarrhythmic death or transplant but similar incidence of SCD as P-HCM. However, ICDs were used less frequently in RAS-HCM compared to P-HCM. In addition to monitoring for heart failure and timely consideration of advanced heart failure therapies, better risk stratification is needed to guide ICD practices in RAS-HCM.

Cardioprotective Actions of a Glucagon-like Peptide-1 Receptor Agonist on Hearts Donated After Circulatory Death.

Background Heart transplantation with a donation after circulatory death (DCD) heart is complicated by substantial organ ischemia and ischemia-reperfusion injury. Exenatide, a glucagon-like peptide-1 receptor agonist, manifests protection against cardiac ischemia-reperfusion injury in other settings. Here we evaluate the effects of exenatide on DCD hearts in juvenile pigs. Methods and Results DCD hearts with 15-minutes of global warm ischemia after circulatory arrest were reperfused ex vivo and switched to working mode. Treatment with concentration 5-nmol exenatide was given during reperfusion. DCD hearts treated with exenatide showed higher myocardial oxygen consumption (exenatide [n=7] versus controls [n=7], over 60-120 minutes of reperfusion, P<0.001) and lower cardiac troponin-I release (27.94±11.17 versus 42.25±11.80 mmol/L, P=0.04) during reperfusion compared with controls. In working mode, exenatide-treated hearts showed better diastolic function (dp/dt min: -3644±620 versus -2193±610 mm Hg/s, P<0.001; Tau: 15.62±1.78 versus 24.59±7.35 milliseconds, P=0.02; lateral e' velocity: 11.27 ± 1.46 versus 7.19±2.96, P=0.01), as well as lower venous lactate levels (3.17±0.75 versus 5.17±1.44 mmol/L, P=0.01) compared with controls. Higher levels of activated endothelial nitric oxide synthase (phosphorylated to total endothelial nitric oxide synthase levels: 2.71±1.16 versus 1.37±0.35, P=0.02) with less histological evidence of endothelial damage (von Willebrand factor expression: 0.024±0.007 versus 0.331±0.302, pixel/µm, P=0.04) was also observed with exenatide treatment versus controls. Conclusions Acute treatment of DCD hearts with exenatide limits myocardial and endothelial injury and improves donor cardiac function.

Diagnostic and Prognostic Value of Myocardial Work Indices for Identification of Cancer Therapy-Related Cardiotoxicity.

BACKGROUND: Echocardiographic global longitudinal strain (GLS) is a useful measure for detection of cancer treatment-related cardiac dysfunction (CTRCD) but is influenced by blood pressure changes. This limitation may be overcome by assessment of myocardial work (MW), which incorporates blood pressure into the calculation. OBJECTIVES: This work aims to determine whether myocardial work indices (MWIs) can help diagnose or prognosticate CTRCD. METHODS: In this prospective cohort study, 136 women undergoing anthracycline and trastuzumab treatment for HER2+ breast cancer, underwent serial echocardiograms and cardiac magnetic resonance pre- and post-anthracycline and every 3 months during trastuzumab. GLS, global work index (GWI), global constructive work (GCW), global wasted work, and global work efficiency were measured. CTRCD was defined with cardiac magnetic resonance. Generalized estimating equations quantified the association between changes in GLS and MWIs and CTRCD at the current (diagnosis) and subsequent visit (prognosis). Regression tree analysis was used to explore the combined use of GLS and MW for the diagnostic/prognostic assessment of CTRCD. RESULTS: Baseline left ventricular ejection fraction (LVEF) was 63.2 ± 4.0%. Thirty-seven (27.2%) patients developed CTRCD. An absolute change in GLS (standardized odds ratio [sOR]: 1.97 [95% CI: 1.07-3.66]; P = 0.031) and GWI (sOR: 1.73 [95% CI: 1.04-2.85]; P = 0.033) were associated with concurrent CTRCD. An absolute change in GLS (sOR: 1.79 [95% CI: 1.22-2.62]; P = 0.003), GWI (sOR: 1.67 [95% CI: 1.20-2.32]; P = 0.003), and GCW (sOR: 1.65 [95% CI: 1.17-2.34]; P = 0.005) were associated with subsequent CTRCD. Change in GWI and GCW demonstrated incremental value over GLS and clinical factors for the diagnosis of concurrent CTRCD. In a small group with a GLS change <3.3% (absolute), and a >21 mm Hg reduction in systolic blood pressure, worsening of GWI identified patients with higher probability of concurrent CTRCD (24.0% vs 5.2%). MWIs did not improve identification of subsequent CTRCD beyond knowledge of GLS change. CONCLUSIONS: GLS can be used to diagnose and prognosticate cardiac magnetic resonance (CMR) defined CTRCD, with additional value from MWIs in selected cases. (Evaluation of Myocardial Changes During Breast Adenocarcinoma Therapy to Detect Cardiotoxicity Earlier With MRI [EMBRACE-MRI]; NCT02306538).

Branch pulmonary artery stenosis after arterial switch operation: The effect of preoperative anatomic factors on reintervention.

BACKGROUND: We hypothesized that preoperative patient characteristics and branch pulmonary artery (PA) size might influence the rate of postoperative branch PA reintervention in patients with transposition of the great arteries who undergo the arterial switch operation (ASO). METHODS: The retrospective single-center study included 262 consecutive (2008-2017) newborns who underwent the ASO. Demographic characteristics, echocardiography, and clinical outcomes were reviewed. Competing risk analysis modeled incidence of branch PA reintervention and cause-specific hazard regression for predictors analyses. RESULTS: Median age and weight were 7 (range, 5-11) days and 3.4 (range, 3.1-3.8) kg, respectively. Various types of early branch PA reinterventions (concomitant revision or reintervention during the intensive care unit stay) were required in 28 (10.7%) patients. These patients had prolonged ventilation (P < .001), intensive care unit duration (P < .001), worse right ventricular function (P = .043), and high in-hospital mortality (P = .010). Branch PA dimensions significantly decreased immediately after ASO compared with baseline measurements. The median follow-up duration was 20.8 (range, 0.9-44.7) months. Branch PA reintervention was common among survivors without early reinterventions (9.4%), and even more frequent among those with early reinterventions (25%). Subsequent reintervention (all catheter-based) was necessary for more than one-third of patients after initial branch PA reintervention. The multivariable analysis showed preoperative dimension of the left PA (hazard ratio, 0.527 [95% CI, 0.337-0.823]; P = .005), and right PA (hazard ratio, 0.503 [95% CI, 0.318-0.796]; P = .003) were independently associated with late branch PA reinterventions. CONCLUSIONS: Branch PA reintervention was common and often required surgical or catheter-based reinterventions after ASO. PA branch diameters became significantly smaller after ASO. Smaller preoperative branch PA predicted late branch PA reintervention, indicating a smaller margin of geometrical tolerance to this effect.

Longitudinal Prediction of Transplant-Free Survival by Echocardiography in Pediatric Dilated Cardiomyopathy.

BACKGROUND: The prognostic significance of serial echocardiography and its rate of change in children with dilated cardiomyopathy (DCM) is incompletely defined. METHODS: We retrospectively analysed up to 4 serial echocardiograms. Associations between mortality/transplant and echocardiographic parameters over time and between outcomes and the rate of change of echocardiographic parameters were analysed. Estimation of patient-specific intercepts and slopes was done using linear regression models. RESULTS: Fifty-seven DCM children were studied (50% male; median age, 0.6 year; average follow-up, 2.1 ± 2.4 years). The median time to transplant or death was 2.0 years. Increased left ventricular (LV) diastolic (LVEDD) and systolic (LVESD) dimensions and myocardial performance index (MPI) were associated with increased mortality and transplant risk. Increased LV ejection fraction, mitral E-deceleration time, right ventricular (RV) fractional area change, and tricuspid annular plane systolic excursion were associated with reduced mortality and transplant risk. Transplant/mortality likelihood increased by 41.6% and 19.8% for each unit increase in LVEDD and LVESD z scores, respectively (LVEDD: hazard ratio [HR], 1.416; 95% confidence interval [CI], 1.285-1.560; P < 0.001; LVESD: HR, 1.198; 95% CI, 1.147-1.251; P < 0.001). A higher monthly change in LVESD z score increased transplant/mortality likelihood by 85.6% (HR, 1.856; 95% CI, 1.572-2.191; P = 0.015). Greater changes in mitral E/e' (HR, 0.707; 95% CI, 0.636-0.786; P < 0.001) and RV MPI (HR, 0.412; 95% CI, 0.277-0.613; P < 0.001) were associated with reduced mortality and transplant risk. CONCLUSIONS: LV and RV systolic and diastolic dimensions and function over time and their rate of change are associated with risk for transplant and mortality in childhood DCM. Serial changes in these parameters may be useful to predict clinical outcomes.

Low preoperative superior vena cava blood flow predicts bidirectional cavopulmonary shunt failure.

BACKGROUND: In this study we sought to determine whether preoperative superior vena cava (SVC) blood flow measured using cardiac magnetic resonance (CMR) predicts physiology and clinical outcome after bidirectional cavopulmonary shunt (BCPS). METHODS: The retrospective single-center study included 65 (2012-2017) patients who underwent BCPS. Preoperative CMR imaging, echocardiography, catheterization, and clinical outcomes were reviewed. SVC flow was measured using phase contrast CMR. The Kaplan-Meier method and Cox regression was used for BCPS takedown-free survival and predictor analyses. RESULTS: The absolute and indexed SVC flow was 0.5 (interquartile range [IQR], 0.4-0.7) L/min and 1.7 (IQR, 1.4-2.0) L/min/mm2 respectively, which was comparable with the SVC blood flow volume previously measured. The median age and body weight at BCPS was 6.5 (IQR, 5.5-8.5) months and 6.9 (IQR, 6.0-7.7) kg. After follow-up, at a median of 17.1 (IQR, 7.9-41.3) months, 14 patients (21.5%) underwent the Fontan completion and 40 (61.5%) with BCPS physiology were waiting for the Fontan completion. The 11 remaining patients (16.9%), included those who underwent takedown (n = 7; 10.8%) or died with a BCPS (n = 4; 6.2%). Severe hypoxia was the leading cause of mortality, directly accounting for two-thirds of deaths (66.6%; 6/9). The BCPS takedown-free survival was 96.8% at 6 months, and 79.9% at 3 years. Preoperative SVC blood flow was significantly positively correlated with early post-BCPS arterial saturation (P = .00). The multivariable analysis showed SVC flow was the only factor associated with BCPS failure (hazard ratio, 0.186; P = .04) among the predictors related to the pre-BCPS anatomy and physiology. CONCLUSIONS: SVC blood flow might be as critically important as pulmonary artery anatomic and physiologic parameters in the evaluation of BCPS candidacy in the single-ventricle population.

A Validated Model for Sudden Cardiac Death Risk Prediction in Pediatric Hypertrophic Cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy is the leading cause of sudden cardiac death (SCD) in children and young adults. Our objective was to develop and validate a SCD risk prediction model in pediatric hypertrophic cardiomyopathy to guide SCD prevention strategies. METHODS: In an international multicenter observational cohort study, phenotype-positive patients with isolated hypertrophic cardiomyopathy <18 years of age at diagnosis were eligible. The primary outcome variable was the time from diagnosis to a composite of SCD events at 5-year follow-up: SCD, resuscitated sudden cardiac arrest, and aborted SCD, that is, appropriate shock following primary prevention implantable cardioverter defibrillators. Competing risk models with cause-specific hazard regression were used to identify and quantify clinical and genetic factors associated with SCD. The cause-specific regression model was implemented using boosting, and tuned with 10 repeated 4-fold cross-validations. The final model was fitted using all data with the tuned hyperparameter value that maximizes the c-statistic, and its performance was characterized by using the c-statistic for competing risk models. The final model was validated in an independent external cohort (SHaRe [Sarcomeric Human Cardiomyopathy Registry], n=285). RESULTS: Overall, 572 patients met eligibility criteria with 2855 patient-years of follow-up. The 5-year cumulative proportion of SCD events was 9.1% (14 SCD, 25 resuscitated sudden cardiac arrests, and 14 aborted SCD). Risk predictors included age at diagnosis, documented nonsustained ventricular tachycardia, unexplained syncope, septal diameter z-score, left ventricular posterior wall diameter z score, left atrial diameter z score, peak left ventricular outflow tract gradient, and presence of a pathogenic variant. Unlike in adults, left ventricular outflow tract gradient had an inverse association, and family history of SCD had no association with SCD. Clinical and clinical/genetic models were developed to predict 5-year freedom from SCD. Both models adequately discriminated between patients with and without SCD events with a c-statistic of 0.75 and 0.76, respectively, and demonstrated good agreement between predicted and observed events in the primary and validation cohorts (validation c-statistic 0.71 and 0.72, respectively). CONCLUSION: Our study provides a validated SCD risk prediction model with >70% prediction accuracy and incorporates risk factors that are unique to pediatric hypertrophic cardiomyopathy. An individualized risk prediction model has the potential to improve the application of clinical practice guidelines and shared decision making for implantable cardioverter defibrillator insertion. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT0403679.

Risk factors associated with treatment discontinuation and down-titration in type 2 diabetes patients treated with sulfonylureas.

OBJECTIVES: Sulfonylurea therapy among patients with type 2 diabetes mellitus (T2DM) can be disrupted due to adverse events, including hypoglycemia. A retrospective study using the MarketScan claims database quantified the frequency of sulfonylurea discontinuation or down-titration and identified associated risk factors. RESEARCH DESIGN AND METHODS: Adult patients with an index sulfonylurea prescription between 2008 and 2012 and 1 year continuous enrollment pre- and post-index were included. Therapy changes assessed over 1 year post-index included discontinuation and down-titration. Discontinuation occurred if the date of a fill was >90 days from the end date of the preceding fill. Down-titration occurred when a fill had a lower equivalent dose than the fill on the index date. Kaplan-Meier methods estimated the probability of either discontinuation or down-titration over 12 months, and Cox regression models identified associated risk factors. RESULTS: A total of 104,082 sulfonylurea users were included in the study and the probability of either discontinuation or down-titration at 3, 6 and 12 months was 23.2%, 38.9%, and 52.3%, respectively. Major risk factors associated with therapy changes included post-index hypoglycemia (discontinuation hazard ratio [HR] = 1.78 [1.68, 1.89]; down-titration HR =2.79 [2.40, 3.23]) and concomitant use of insulin (discontinuation HR =1.48 [1.40, 1.57]; down-titration HR =1.82 [1.56, 2.11]). Other risk factors included younger age, female gender, use of second generation sulfonylureas, prior cardiovascular comorbidity and liver disease. LIMITATIONS: The study was not able to assess unreported, potentially mild cases of hypoglycemia, nor was it able to evaluate the association between changes in therapy and HbA1c levels or body weight. CONCLUSIONS: More than half of T2DM patients who initiated sulfonylurea therapy discontinued or down-titrated within 1 year. Insulin use and hypoglycemia were associated with sulfonylurea therapy change.

Gastrointestinal Events Among Patients Initiating Osteoporosis Therapy: A Retrospective Administrative Claims Database Analysis.

PURPOSE: Our purpose was to characterize the occurrence of gastrointestinal (GI) events among women on oral bisphosphonate therapy. METHODS: This was a retrospective cohort study that used a United States (US) claims database. The study period was from January 1, 2000, to December 31, 2011. The index date was the date of the first oral bisphosphonate (alendronate, ibandronate, or risedronate) prescription and occurred between January 1, 2001, and December 31, 2010. The pre- and post-index periods were the 1-year periods before and after the index date, respectively. The analysis included women with osteoporosis aged ≥55 years at the index date who were naive to all osteoporosis treatments before the index date and were continuously enrolled in the health plan for at least 1 year before and 1 year after the index date. Patients with a diagnosis of malignant neoplasm during the pre- or post-index periods or a diagnosis of Paget disease anytime in the claims history were excluded. The occurrence of GI events (defined as esophagitis; gastroesophageal reflux disease; ulcer, stricture, perforation, or hemorrhage of the esophagus; gastric, duodenal, or peptic ulcer; acute gastritis; duodenitis; GI hemorrhage; nausea/vomiting; or dysphagia) was assessed during the pre-index period and at 3, 6, and 12 months in the post-index period. The rate of GI events was defined as the percentage of patients having at least 1 GI event in each analysis period (ie, pre-index and post-index periods). GI events in the post-index period were also stratified by the presence of GI events in the pre-index period. FINDINGS: A total of 75,593 women were included in the analysis. The average age at the index date was 64.4 years. Gastroprotective agents were used by 17.9% of patients. Approximately one fourth of patients (26.6%; n = 20,073) had ≥1 GI events in the pre-index period. Approximately the same proportion of patients (28.0%; n = 21,142) experienced GI events in the post-index period. The cumulative rate of GI events during the post-index period was higher among patients who had GI events in the pre-index period (51.2%) than among patients without a GI event in the pre-index period (19.6%). IMPLICATIONS: Among women with osteoporosis enrolled in a US commercial plan, GI events were common regardless of bisphosphonate use. Approximately one fourth of US women on bisphosphonate therapy experienced GI events within the year after initiation of therapy, and one half of US women with a previous GI event had another event while taking bisphosphonates.