How Accurate is Clinical Assessment of Neck Veins in the Estimation of Central Venous Pressure in Acute Heart Failure? Insights From a Prospective Study

Medical history and physical examination are the primary diagnostic tools when assessing emergency department (ED) patients with suspected acute heart failure (AHF). Among physical signs, positive hepato-jugular reflux (HJR) and jugular vein distention (JVD) are considered to indicate elevated central venous pressure (CVP). Both are major Framingham heart failure criteria and evaluated with priority in dyspnoeic patients presenting to the ED. Unfortunately and in contrast to common perception, the accuracy of clinical neck vein assessment in estimating CVP in AHF patients presenting to the ED is largely unknown. This is a dilemma as treatment decisions are commonly based on estimating CVP from assessing neck veins in AHF. The recent development and validation of a non-invasive forearm vein compression ultrasound technique to reliably measure CVP1, 2 allowed us to address this gap in knowledge and to evaluate the diagnostic accuracy of clinical neck vein examination for the detection of elevated CVP in AHF patients at ED presentation. This sub-study of the Basics in Acute Shortness of Breath Evaluation Study (ClinicalTrials.gov identifier: NCT01831115) prospectively enrolled adult AHF patients at the time of ED presentation. Only patients with a final adjudicated diagnosis of AHF were included in this analysis. The study was approved by the local ethics committee, and patients gave written informed consent. At the time of presentation a physical examination was performed and documented by the treating ED physician using the standardized case report form used universally at the University Hospital Basel. Findings of the examination of the jugular veins were categorized as: normal (HJR–/JVD–), distended after provocation by HJR (HJR+), distended at rest (JVD+). Physicians were blinded to the measurements of CVP and were not aware of the research aim to compare their assessment to the actual measurement of CVP. Immediately after physical examination by the treating ED physician, CVP was measured by a vascular specialist as described previously.1, 2 The vascular specialist performing compression sonography was blinded to the clinician's neck vein assessment and was not directly involved in routine patient care. Measurement of CVP was only recorded for the purpose of this study and the clinical care team remained blinded to its results. Overall, 217 patients were included in the analysis and CVP measurements were performed within a median of 2.8 h after ED presentation. The study population was elderly (median age: 80 years). At presentation, median B-type natriuretic peptide (BNP) blood concentration was 1150 pg/mL and median echocardiographic left ventricular ejection fraction was 39%, with 51% of patients suffering from heart failure with reduced ejection fraction. Tricuspid annular plane systolic excursion in the overall population was mildly impaired [16 mm, interquartile range (IQR) 13–20]. ED physicians classified neck veins as normal in 67 (31%), HJR+ in 26 (12%), and JVD+ in 124 (57%) patients. HJR+ and JVD+ patients differed only in the frequency of peripheral oedema (71% vs. 65%, P = 0.02). However, HJR+ or JVD+ patients more frequently presented with other clinical signs of AHF, tended to have higher BNP blood concentrations, and more frequently had already received outpatient diuretic therapy. In a logistic regression analysis, only AHF signs [peripheral oedema: odds ratio (OR) 3.48, P < 0.01; rales: OR 2.07, P = 0.02; congestion on X-ray: OR 2.06, P = 0.02; lgBNP: OR 2.29, P = 0.04; outpatient diuretics: OR 2.18, P = 0.02] and lower body weight (OR 0.98, P = 0.04) but not CVP (P = 0.71) were significantly associated with HJR+ or JVD+ documentation by the ED physician. Median CVP was 8.8 mmHg (IQR 5.9–12.6). CVP values in the three groups were identical [HJR–/JVD–: median 8.8 (IQR 6.7–13.3) mmHg; HJR+: 7.4 (IQR 5.0–13.5) mmHg; JVD+: 9.6 (IQR 5.9-12.6) mmHg] (P = 0.65) (Figure 1). Sensitivity and specificity of HJR+/JVD+ to detect elevated CVP was poor. HJR+/JVD+ achieved a sensitivity of 68.5% and a specificity of 28.2% to detect CVP levels above 5 mmHg. Diagnostic accuracies for HJR+ (sensitivity 11.2%, specificity 84.6%) and JVD+ (sensitivity 57.3%, specificity 43.6%) were similarly poor for the detection of CVP elevations above 5 mmHg. Sensitivity (67.8%) and specificity (30.4%) of HJR+/JVD+ remained poor even for CVP levels above 12 mmHg. Linear regression analysis showing factors associated with CVP elevations is shown in Table 1. To the best of our knowledge, this is the first prospective study assessing the diagnostic accuracy of clinical neck vein examination for the detection of elevated CVP in AHF patients at the time of ED presentation. We report six findings: first, pathologic neck vein examination is documented by the treating ED physician in more than two-thirds of AHF patients. Second, neck vein examination was not found to be associated with actual CVP measurements. In fact, CVP was similar in patients with normal neck veins, HJR+ and JVD+ patients. Accordingly, pathologic neck vein examinations lacked sensitivity (68.5%) and specificity (28.2%) in diagnosing elevated CVP. Third, clinical signs and laboratory parameters indicative of AHF were significantly associated with the documentation of pathologic findings on neck vein examination. This suggests that ED physicians extrapolate neck vein findings from other AHF signs that may be easier to assess. Fourth, while CVP elevation is very common in AHF patients, occurring in over 80% of patients, clinical signs and laboratory parameters indicative of AHF do not allow to reliably predict CVP elevation. Fifth, higher body weight was significantly associated with a lower likelihood of HJR+/JVD+ documentation, in part reflecting the challenge to examine neck veins in obese patients. Sixth, higher body weight was an independent predictor of higher CVP levels. This may at least partly be caused by an expansion of the intravascular volume in obese patients. Impaired right ventricular function was the only other additional factor significantly associated with increasing CVP levels. In conclusion, clinical neck vein examination is inaccurate in the assessment of CVP in AHF. ED physicians seem to extrapolate neck vein findings from other AHF signs. This work was supported by a research grant from the Swiss National Science Foundation, the Swiss Heart Foundation, the University of Basel, and the Cardiovascular Foundation Basel (all to CM) and a research grant from the University of Basel to HU. Conflict of interest: none declared.