Should Oscillometric Blood Pressure Monitors Be Used in Patients With Atrial Fibrillation?

Hemodynamic effects of Vernakalant in cardio-surgical ICU-patients treated for recent-onset postoperative atrial fibrillation

Postoperative atrial fibrillation (POAF) is one of the most frequent complications after cardiothoracic surgery and a predictor for postoperative mortality and prolonged ICU-stay. Current guidelines suggest the multi-channel inhibitor Vernakalant as a treatment option for rhythm control. However, rare cases of severe hypotension and cardiogenic shock following drug administration have been reported. To elucidate the impact of Vernakalant on hemodynamics, we included ten ICU patients developing POAF after elective cardiac surgery, all of them awake and breathing spontaneously, in this prospective trial. Patients received the recommended dosage of Vernakalant and were clinically observed and monitored (heart rate, invasive blood pressure, pulse oximetry, central venous pressure) in 1-minute-intervals for 20 minutes before- and 120 minutes after the first dose of Vernakalant. The median time from the end of surgery until occurrence of POAF amounted up to 52.8 [45.9–77.4] hours, it took 3.5 [1.2–10.1] hours from occurrence of POAF until the first application of Vernakalant. All patients received catecholamine support with epinephrine that was held steady and not dynamic throughout the observational phase. We noted stable hemodynamic conditions, with a trend towards a reduction in heart rate throughout the 120 minutes after drug administration. In 7 patients (70%), conversion to sustained sinus rhythm (SR) occurred within 8.0 minutes [6.0–9.0]. No serious adverse events (SAEs) were noted during the observation period. In this prospective trial in ICU-patients showing POAF after cardiac surgery, intravenous Vernakalant did not induce clinically relevant negative effects on patients’ hemodynamics but resulted in conversion to sustained SR after a median of 8.0 minutes in 7 out of ten patients.

The impact of atrial fibrillation on accuracy of oscillometric blood pressure measurement: effect of ventricular rate

This study evaluated the impact of ventricular rate (VR) in atrial fibrillation (AF) patients with oscillometric BP measurements. This study included 138 patients with AF and 112 patients with sinus rhythm (SR) who underwent coronary angiography. Left arm BP was measured three times with an oscillometric device, and the average was recorded as the final oscillometric value. At the same time, the average of three intra-aortic BP readings was used as invasive values. Delta BP was the difference between intra-aortic and oscillometric BP. Meanwhile, the BP percentage difference (PD-BP) was calculated with the following formula: PD-BP = (delta BP/intra-aortic BP) × 100%. Based on the VR, four subgroups of AF and SR patients, <80, 80-99, 100-120, and >120 bpm, were created, and the mean PD-BP for both systolic blood pressure (SBP) and diastolic blood pressure (DBP) was significantly higher in the AF group than in the SR group. Moreover, the mean PD-SBP values gradually increased as VR increased in both groups. More importantly, the difference in PD-SBP between the AF and SR groups increased as VR increased: when VR was <80 bpm, the levels were similar (-2.0 ± 3.5 vs. -1.4 ± 2.7 mm Hg, NS), but these values in AF patients were significantly higher when VR was 80-99 bpm (-3.7 ± 5.0 vs. -1.8 ± 2.3 mm Hg, p < 0.05), 100-120 bpm (-6.1 ± 4.3 vs. -2.3 ± 1.9 mm Hg, p < 0.05) and >120 bpm (-7.8 ± 4.9 vs. -2.9 ± 1.7 mm Hg, p < 0.05). The accuracy of oscillometric BP measurements are dependent on the ventricular rate in AF patients even after three measurements, and a higher ventricular rate may result in larger underestimations of oscillometric BP.

Accuracy of automated blood pressure measurements in the presence of atrial fibrillation: systematic review and meta-analysis

Atrial fibrillation (AF) affects ~3% of the general population and is twice as common with hypertension. Validation protocols for automated sphygmomanometers exclude people with AF, raising concerns over accuracy of hypertension diagnosis or management, using out-of-office blood pressure (BP) monitoring, in the presence of AF. Some devices include algorithms to detect AF; a feature open to misinterpretation as offering accurate BP measurement with AF. We undertook this review to explore accuracy of automated devices, with or without AF detection, for measuring BP. We searched Medline and Embase to October 2018 for studies comparing automated BP measurement devices to a standard mercury sphygmomanometer contemporaneously. Data were extracted by two reviewers. Mean BP differences between devices and mercury were calculated, where not reported and compared; meta-analyses were undertaken where possible. We included 13 studies reporting 14 devices. Mean systolic and diastolic BP differences from mercury ranged from -3.1 to + 6.1/-4.6 to +9.0 mmHg. Considerable heterogeneity existed between devices (I²: 80 to 90%). Devices with AF detection algorithms appeared no more accurate for BP measurement with AF than other devices. A previous review concluded that oscillometric devices are accurate for systolic but not diastolic BP measurement in AF. The present findings do not support that conclusion. Due to heterogeneity between devices, they should be evaluated on individual performance. We found no evidence that devices with AF detection measure BP more accurately in AF than other devices. More home or ambulatory automated BP monitors require validation in populations with AF.

The design, rationale, and baseline characteristics of a nationwide cohort registry in China: blood pressure and clinical outcome in TIA or ischemic stroke

BACKGROUND

The relationship between poststroke blood pressure (BP) and clinical outcomes in ischemic stroke (IS) is still controversial. However, there is no large BP database for IS or transient ischemic attack (TIA) in China. This study aims to describe the rationale, study design, and baseline characteristics of a nationwide BP database in IS or TIA patients in China.

MATERIALS AND METHODS

The BOSS (blood pressure and clinical outcome in TIA or ischemic stroke) study was a hospital-based, prospective cohort study aiming to assess BP parameters and clinical outcome in IS/TIA patients. BP parameters were based on office BP, ambulatory BP, and home BP. Clinical outcomes included stroke recurrence, combined vascular events, and disability. Electronic case-report forms were used to record baseline and follow-up data. The patients were followed up for clinical outcomes at 3 months through face-to-face interview and at 12 months by telephone.

RESULTS

Between October 2012 and February 2014, the BOSS registry recruited 2,608 patients from 61 hospitals, with a mean age of 62.5 years, 32.4% of whom were female, 88.9% with an entry diagnosis of IS, and 86% diagnosed with hypertension. The rates of patients lost-to-follow-up were 3.1% at 3 months and 5.1% at 1 year; 93% of patients completed ambulatory BP monitoring during hospitalization and 94.7% finished a 3-month BP diary.

CONCLUSION

The BOSS registry will provide important evidence about BP management in the acute phase and secondary prevention for IS/TIA patients.