Computed tomography or chest X-ray to assess pulmonary congestion in dyspnoeic patients with acute heart failure

AIMS

While computed tomography (CT) is widely acknowledged as superior to chest radiographs for acute diagnostics, its efficacy in diagnosing acute heart failure (AHF) remains unexplored. This prospective study included consecutive patients with dyspnoea undergoing simultaneous low-dose chest CT (LDCT) and chest radiographs. Here, we aimed to determine if LDCT is superior to chest radiographs to confirm pulmonary congestion in dyspnoeic patients with suspected AHF.

METHODS AND RESULTS

An observational, prospective study, including dyspnoeic patients from the emergency department. All patients underwent concurrent clinical examination, laboratory tests, echocardiogram, chest radiographs, and LDCT. The primary efficacy measure to compare the two radiological methods was conditional odds ratio (cOR). The primary outcome was adjudicated AHF, ascertained by comprehensive expert consensus. The secondary outcome, echo-bnp AHF, was an objective AHF diagnosis based on echocardiographic cardiac dysfunction, elevated cardiac filling pressure, loop diuretic administration, and NT-pro brain natriuretic peptide > 300 pg/mL. Of 228 dyspnoeic patients, 64 patients (28%) had adjudicated AHF, and 79 patients (35%) had echo-bnp AHF. Patients with AHF were older (78 years vs. 73 years), had lower left ventricular ejection fraction (36% vs. 55%), had higher elevated left ventricular filling pressures (98% vs. 18%), and had higher NT-pro brain natriuretic peptide levels (3628 pg/mL vs. 470 pg/mL). The odds to diagnose adjudicated AHF and echo-bnp AHF were up to four times greater using LDCT (cOR: 3.89 [2.15, 7.06] and cOR: 2.52 [1.45, 4.38], respectively). For each radiologic sign of pulmonary congestion, the LDCT provided superior or equivalent results as the chest radiographs, and the interrater agreement was higher using LDCT (kappa 0.88 [95% CI: 0.81, 0.95] vs. 0.73 [95% CI: 0.63, 0.82]). As first-line imaging modality, LDCT will find one additional adjudicated AHF in 12.5 patients and prevent one false-positive in 20 patients. Similar results were demonstrated for echo-bnp AHF.

CONCLUSIONS

In consecutive dyspnoeic patients admitted to the emergency department, LDCT is significantly better than chest radiographs in detecting pulmonary congestion.

Remote dielectric sensing to detect acute heart failure in patients with dyspnoea: a prospective observational study in the emergency department

AIMS

Remote dielectric sensing (ReDS) enables quick estimation of lung fluid content. To examine if ReDS is superior to other methods in detecting acute heart failure.

METHODS AND RESULTS

We included consecutive patients with dyspnoea from the emergency departments at Bispebjerg Hospital, Copenhagen, and performed ReDS, low-dose chest computed tomography (CT), echocardiogram, lung ultrasound, NT-Pro-brain natriuretic peptide (NT-proBNP), and a Boston score evaluation (chest X-ray and clinical signs). ReDS values >35% were used as a cut-off to diagnose pulmonary congestion. Acute heart failure was adjudicated by experts' review of health records but independently of ReDS values. Sub-analyses investigated ReDS in acute heart failure patients with congestion on CT. We included 97 patients within a median of 4.8 h from admittance: 25 patients (26%) were ReDS-positive and 39 (40%) had adjudicated acute heart failure (21 with and 18 without CT congestion). Heart failure patients had median ReDS 33%, left ventricular ejection fraction 48%, and NT-proBNP 2935 ng/L. A positive ReDS detected heart failure with 46% sensitivity, 88% specificity, and 71% accuracy. The AUC for ReDS was like the Boston score (P = 0.88) and the lung ultrasound score (P = 0.74). CT-congested heart failure patients had higher ReDS values than patients without heart failure (median 38 vs. 28%, P < 0.001). Heart failure patients without CT-congestion had ReDS values like patients without heart failure (mean 30 vs. 28%, P = 0.07).

CONCLUSION

ReDS detects acute heart failure similarly to the Boston score and lung ultrasound score, and ReDS primarily identifies the acute heart failure patients who have congestion on a chest CT.

Chest computed tomography features of heart failure: A prospective observational study in patients with acute dyspnea

BACKGROUND

Pulmonary congestion is a key component of heart failure (HF) that chest computed tomography (CT) can detect. However, no guideline describes which of many anticipated CT signs are most associated with HF in patients with undifferentiated dyspnea.

METHODS

In a prospective observational single-center study, we included consecutive patients ≥ 50 years admitted with acute dyspnea to the emergency department. Patients underwent immediate clinical examination, blood sampling, echocardiography, and CT. Two radiologists independently evaluated all images. Acute HF (AHF) was adjudicated by an expert panel blinded to radiology images. Lasso and logistic regression identified the independent CT signs of AHF.

RESULTS

Among 232 patients, 102 (44%) had AHF. Of 18 examined CT signs, 5 were associated with AHF (multivariate odds ratio, 95% confidence interval): enlarged heart (20.38, 6.86-76.16), bilateral interlobular thickening (11.67, 1.78-230.99), bilateral pleural effusion (6.39, 1.98-22.85), and increased vascular diameter (4.49, 1.08-33.92). Bilateral ground-glass opacification (2.07, 0.95-4.52) was a consistent fifth essential sign, although it was only significant in univariate analysis. Eighty-eight (38%) patients had none of the five CT signs corresponding to a 68% specificity and 86% sensitivity for AHF, while two or more of the five CT signs occurred in 68 (29%) patients, corresponding to 97% specificity and 67% sensitivity. A weighted score based on these five CT signs had an 0.88 area under the curve to detect AHF.

CONCLUSIONS

Five CT signs seem sufficient to assess the risk of AHF in the acute setting. The absence of these signs indicates a low probability, one sign makes AHF highly probable, and two or more CT signs mean almost certain AHF.