Question What are the key similarities and differences in characteristics, comorbidities, therapies, and in-hospital outcomes in patients with chronic and acute heart failure? Findings In this cohort study including 18& x202f;553 patients from 7 global regions, there were similarities in many regions regarding prevalence of prior heart failure, ejection fraction, and comorbidities. However, there were key differences in outpatient treatment, hospital point of entry, acute heart failure precipitants, and timing and type of inpatient intravenous therapies. Meaning These data provide information on the current global burden of acute heart failure, identify region-specific gaps in management, and note differences in practice around the world associated with patient outcomes. This cohort study compares the characteristics and management of acute heart failure in global regions comprising 44 countries. Importance Acute heart failure (AHF) precipitates millions of hospital admissions worldwide, but previous registries have been country or region specific. Objective To conduct a prospective contemporaneous comparison of AHF presentations, etiologic factors and precipitants, treatments, and in-hospital outcomes among global regions through the International Registry to Assess Medical Practice with Longitudinal Observation for Treatment of Heart Failure (REPORT-HF). Design, Setting, and Participants A total of 18& x202f;553 adults were enrolled during a hospitalization for AHF. Patients were recruited from the acute setting in Western Europe (WE), Eastern Europe (EE), Eastern Mediterranean and Africa (EMA), Southeast Asia (SEA), Western Pacific (WP), North America (NA), and Central and South America (CSA). Patients with AHF were approached for consent and excluded only if there was recent participation in a clinical trial. Patients were enrolled from July 23, 2014, to March 24, 2017. Statistical analysis was conducted from April 18 to June 29, 2018; revised analyses occurred between August 6 and 29, 2019. Main Outcomes and Measures Heart failure etiologic factors and precipitants, treatments, and in-hospital outcomes among global regions. Results A total of 18& x202f;553 patients were enrolled at 358 sites in 44 countries. The median age was 67.0 years (interquartile range [IQR], 57-77), 11& x202f;372 were men (61.3%), 9656 were white (52.0%), 5738 were Asian (30.9%), and 867 were black (4.7%). A history of HF was present in more than 50% of the patients and 40% were known to have a prior left-ventricular ejection fraction lower than 40%. Ischemia was a common AHF precipitant in SEA (596 of 2329 [25.6%]), WP (572 of 3354 [17.1%]), and EMA (364 of 2241 [16.2%]), whereas nonadherence to diet and medications was most common in NA (306 of 1592 [19.2%]). Median time to the first intravenous therapy was 3.0 (IQR, 1.4-5.6) hours in NA; no other region had a median time above 1.2 hours (P < .001). This treatment delay remained after adjusting for severity of illness (P < .001). Intravenous loop diuretics were the most common medication administered in the first 6 hours of AHF management across all regions (65.4%-89.9%). Despite similar initial blood pressure across all regions, inotropic agents were used approximately 3 times more often in SEA, WP, and EE (11.3%-13.5%) compared with NA and WE (3.1%-4.3%) (P < .001). Older age (odds ratio [OR], 1.0; 95% CI, 1.00-1.02), HF etiology (ischemia: OR, 1.65; 95% CI, 1.11-2.44; valvular: OR, 2.10; 95% CI, 1.36-3.25), creatinine level greater than 2.75 mg/dL (OR, 1.85; 95% CI, 0.71-2.40), and chest radiograph signs of congestion (OR, 2.03; 95% CI, 1.39-2.97) were all associated with increased in-hospital mortality. Similarly, younger age (OR, -0.04; 95% CI, -0.05 to -0.02), HF etiology (ischemia: OR, 0.77; 95% CI, 0.26-1.29; valvular: OR, 2.01; 95% CI, 1.38-2.65), creatinine level greater than 2.75 mg/dL (OR, 1.16; 95% CI, 0.31-2.00), and chest radiograph signs of congestion (OR, 1.02; 95% CI, 0.57-1.47) were all associated with increased in-hospital LOS. Conclusions and Relevance Data from REPORT-HF suggest that patients are similar across regions in many respects, but important differences in timing and type of treatment exist, identifying region-specific gaps in medical management that may be associated with patient outcomes.