## 3 Results  
A total of 90 patients with (acute heart failure) AHF were included, with a mean age of 84.5 \(\pm\) 6 years; 48% were women. According to baseline NYHA functional classification, 15.6% were class I, 66.7% class II, 16.6% class III, and 1.1% class IV. Hypertension (86.7%) and atrial fibrillation (75.6%) were the most frequent comorbidities, followed by dyslipidemia (57.8%), CKD (35.6%), diabetes (34.4%), and chronic obstructive pulmonary disease (25.6%). The cohort was predominantly treated with loop diuretics (75.6%), beta-blockers (65.5%), and renin-angiotensin system blockers (53.3%) prior to admission. ISGLT2 use was present in only 28.9% of the sample at the time of the initial assessment. Sixty patients (67%) had HFpEF, and thirty (33%) had HFrEF. At admission, 35% had orthopnea at rest, 28% with two pillows, and 28% with one. Peripheral edema was moderate-to-severe in 52%, and 83% had jugular vein distention > 6 cm (Figure 1). Clinical congestion scores were similar between groups (median 4 points in HFpEF vs. 5 points in HFrEF; \(p\) = 0.119). Lung ultrasound revealed the presence of B-lines in all evaluated patients. These were bilateral in 95% of patients with preserved left ventricular ejection fraction (HFpEF) and in 93% of those with reduced ejection fraction (HFrEF). Pleural effusion was observed in 52% of the HFpEF group, compared to 77% in the HFrEF group. Similarly, ascites was detected via abdominal ultrasound in 5% of HFpEF patients and 20% of HFrEF patients. IVC measurements were comparable between groups. Patients with HFpEF had a mean IVC diameter of 22.4 mm \(\pm\) 4.3 mm, with a collapse < 50% in 78% of cases. Those with HFrEF had a mean diameter of 22.8 mm \(\pm\) 4.8 mm, and 70% exhibited a collapse < 50%. It is important to highlight that, of the 90 patients included in our study, the VExUS protocol was successfully performed in 80 individuals. In the remaining 10 cases, inadequate acoustic windows made it technically impossible to obtain Doppler waveforms from one or more of the venous structures required for scoring--primarily the intrarenal veins. Figure 1: Degree of clinical congestion upon admission. Since complete evaluation is necessary for accurate classification, no VExUS grade was assigned when any component was missing. Regarding hepatic vein Doppler assessment, no statistically significant differences were found (\(p\) = 0.242). Among HFpEF patients, 26% had normal flow, 41% showed moderate alterations, and 33% had severely abnormal flow. In the HFrEF group, these figures were 12%, 58%, and 30%, respectively. Similarly, no significant differences were observed in portal vein Doppler patterns (\(p\) = 0.355). In the HFpEF group, 35% had normal flow, 43% showed pulsatility \(<\) 50%, and 22% had pulsatility \(>\) 50%. In HFrEF patients, 24% had normal flow, 43% had pulsatility \(<\) 50%, and 43% showed pulsatility \(>\) 50%. As for intrarenal venous flow, the distribution was also similar (\(p\) = 0.839). In HFpEF patients, 55% exhibited continuous flow and 45% discontinuous flow (35% biphasic, 10% monophasic). In the HFrEF group, 63% had continuous flow and 37% discontinuous flow (30% biphasic, 7% monophasic) (Figure 2). According to the VExUS classification, among patients with preserved ejection fraction (HFpEF), 20% were classified as grade 0 (no congestion), 39% as grade 1 (mild congestion), 26% as grade 2 (moderate congestion), and 15% as grade 3 (severe congestion). In the reduced ejection fraction group (HFrEF), 19% were classified as grade 0, 31% as grade 1, 38% as grade 2, and 12% as grade 3 (Figure 3). When the cohort was dichotomized into low (VExUS grades 0-1) and moderate-to-severe (VExUS grades 2-3) congestion, 59% of HFpEF patients fell into the low-congestion group and 41% into the higher-congestion group. Among HFrEF patients, the distribution was evenly split (50% vs. 50%). Figure 3: VExUS protocol according to LVEF. Figure 2: VExUS assessment. Suprahepatic, portal, and renal veins according to LVEF.