Reimagining the Value of Brachial-Ankle Pulse Wave Velocity as a Biomarker of Cardiovascular Disease Risk-A Call to Action on Behalf of VascAgeNet.

This review critiques the literature supporting clinical assessment and management of cardiovascular disease and cardiovascular disease risk stratification with brachial-ankle pulse wave velocity (baPWV). First, we outline what baPWV actually measures-arterial stiffness of both large central elastic arteries and medium-sized muscular peripheral arteries of the lower limb. Second, we argue that baPWV is not a surrogate for carotid-femoral pulse wave velocity. While both measures are dependent on the properties of the aorta, baPWV is also strongly dependent on the muscular arteries of the lower extremities. Increased lower-extremity arterial stiffness amplifies and hastens wave reflections at the level of the aorta, widens pulse pressure, increases afterload, and reduces coronary perfusion. Third, we used an established evaluation framework to identify the value of baPWV as an independent vascular biomarker. There is sufficient evidence to support (1) proof of concept; (2) prospective validation; (3) incremental value; and (4) clinical utility. However, there is limited or no evidence to support (5) clinical outcomes; (6) cost-effectiveness; (8) methodological consensus; or (9) reference values. Fourth, we address future research requirements. The majority of the evaluation criteria, (1) proof of concept, (2) prospective validation, (3) incremental value, (4) clinical utility and (9) reference values, can be supported using existing cohort datasets, whereas the (5) clinical outcomes and (6) cost-effectiveness criteria require prospective investigation. The (8) methodological consensus criteria will require an expert consensus statement. Finally, we finish this review by providing an example of a future clinical practice model.

Comparison and Combination of Single-Lead ECG and Photoplethysmography Algorithms for Wearable-Based Atrial Fibrillation Screening.

Background: Atrial fibrillation (AF), the most common cardiac arrhythmia, can be detected by smartphones and smartwatches. Introduction: Single-lead ECGs (iECGs) and photoplethysmography (PPG) sensors provide the opportunity for a broad, simple, and easily repeatable cardiac rhythm analysis. To reduce unnecessary medical follow-up testing due to false positive results, our aim was to find a screening approach applicable on smart devices with a focus on high specificity. Methods: We used PPG measurements from smartphones and smartwatches and iECG data from two previous validation trials. Two AF detection algorithms (A and B) were applied on the iECG dataset and compared directly. Further, we used 1-min PPG measurements as a first-pass filter for arrhythmia detection and simulated a sequential testing: Once an arrhythmia was detected in the PPG, the iECG counterpart of the patient was analyzed by algorithm A, B, or A + B combined although algorithm B was primarily designed for PPG analysis. Results: The iECGs from 1,288 participants were analyzed. Algorithm A did not show a diagnosis in 16.1%. In the remaining, sensitivity and specificity were 99.6%, and 97.4% respectively. Accuracy was 98.5%, and correct classification rate (CCR) was 82.7%. Algorithm B always differentiated between normal and arrhythmic and reached an overall sensitivity of 95.4%, a specificity of 91.6%, and an accuracy and CCR of 93.3%. Sequential testing by combining both algorithms into a three-phase test (Test positive PPG, then iECG analysis by A and B combined) resulted in a 100% specificity. Conclusion: Algorithm B performed strongly in PPG analysis as well as iECG analysis. PPG signals and consecutive iECG combined when an arrhythmia was detected by PPG resulted in a specificity that was higher than 99%. Discussion: The analysis allows a direct comparison of iECG algorithms without possible dilution by different measurement procedures or recording-devices. We improved specificity in AF-screening approaches with wearables by simulating a novel approach. Results rely on signal quality.

Incremental effects of endocrine and metabolic biomarkers and abdominal obesity on cardiovascular mortality prediction.

BACKGROUND: Biomarkers may help clinicians predict cardiovascular risk. We aimed to determine if the addition of endocrine, metabolic, and obesity-associated biomarkers to conventional risk factors improves the prediction of cardiovascular and all-cause mortality. METHODOLOGY/PRINCIPAL FINDINGS: In a population-based cohort study (the Study of Health in Pomerania) of 3,967 subjects (age 20-80 years) free of cardiovascular disease with a median follow-up of 10.0 years (38,638 person-years), we assessed the predictive value of conventional cardiovascular risk factors and the biomarkers thyrotropin; testosterone (in men only); insulin-like growth factor-1 (IGF-1); hemoglobin A1c (HbA1c); creatinine; high-sensitive C-reactive protein (hsCRP); fibrinogen; urinary albumin-to-creatinine ratio; and waist-to-height ratio (WHtR) on cardiovascular and all-cause death. During follow-up, we observed 339 all-cause including 103 cardiovascular deaths. In Cox regression models with conventional risk factors, the following biomarkers were retained as significant predictors of cardiovascular death after backward elimination: HbA1c, IGF-1, and hsCRP. IGF-1 and hsCRP were retained as significant predictors of all-cause death. For cardiovascular death, adding these biomarkers to the conventional risk factors changed the C-statistic from 0.898 to 0.910 (p = 0.02). The net reclassification improvement was 10.6%. For all-cause death, the C-statistic changed from 0.849 to 0.853 (P = 0.09). CONCLUSIONS/SIGNIFICANCE: HbA1c, IGF-1, and hsCRP predict cardiovascular death independently of conventional cardiovascular risk factors. These easily assessed endocrine and metabolic biomarkers might improve the ability to predict cardiovascular death.

Percutaneous laser-facilitated thrombectomy: an innovative, easily applied, and effective therapeutic option for recanalization of acute and subacute thrombotic hemodialysis shunt occlusions.

PURPOSE: To report our experience with excimer laser-facilitated recanalization of acute and subacute thrombotic occlusions of hemodialysis shunts. METHODS: Twenty-one patients (16 women; mean age 54+/-19 years, range 31-76) presented with acute and subacute thrombotic occlusions of their hemodialysis shunts (4 Cimino, 17 prosthetic; 18 forearm, 3 upper arm); mean occlusion time was 4.1+/-3 days (range 1-14), and the thrombotic occlusion measured a mean 17.4+/-9 cm (range 5-27). Fresh thrombus was observed in addition to the total shunt occlusion in all cases. All patients were treated initially with a pulsed ultraviolet (308-nm) excimer laser. Eighteen (85.7%) patients received adjunctive local thrombolysis for treatment of residual thrombus. Nineteen (90.5%) patients underwent angioplasty of the underlying anastomotic stenosis. RESULTS: The angiographic occlusion was reduced from 100% to 63%+/-28% after laser treatment and to 36%+/-18% after 1 hour of thrombolytic therapy (20 mg tissue plasminogen activator). TIMI flow increased significantly from grade 0 to 2.7+/-0.5 following laser ablation (p<0.001) and to 3.0+/-0.2 upon completion of the angioplasty procedure (p>0.001 versus baseline). The immediate procedural success was 95.2% (20/21). Detectable thrombotic embolization and laser-related complications were not observed in any case. Primary patency was 85%; 3 patients had abnormal Doppler flow within 6 weeks and underwent reintervention (secondary patency 100%). All successfully treated shunts were usable for further dialysis at the 6-week follow-up. CONCLUSION: Percutaneous excimer laser-facilitated thrombus vaporization is safe and effective for recanalization of acute and subacute thrombotic occlusions of hemodialysis shunts.