Thirty Days of Home Blood Pressure Monitoring in Patients Following Carotid Endarterectomy: A Feasibility Study

Objectives: Hemodynamic disturbances are the causative mechanism in half the perioperative strokes following Carotid Endarterectomy (CEA). Nevertheless, insight into individual hemodynamics after discharge is lacking. We assessed the feasibility of daily post-discharge Blood Pressure (BP) self-measurements at home following CEA and analyzed BP-trend patterns as well as patient experiences. Methods: Thirty CEA-patients (age 68 ± 8 years; 87% male) measured BP at home twice daily for 30 days with an ambulatory BP-monitor. Exclusion criteria: Modified Rankin Scale score >2 or no access to Wi-Fi. BP-values were transmitted to an online dashboard on a web application. If individually determined systolic target BP exceeded by ≥ 15% an alert was generated, and patients were requested to visit the outpatient clinic after 4 consecutive alerts. After 30 days, patients completed a survey regarding their experiences and perceived feasibility of home BP-monitoring. Adherence to the monitoring protocol, BP time-series, and any interventions were scored. Results: Post-discharge, four adverse events occurred; bleeding requiring surgery (n=1), TIA (n=1), myocardial infarction (n=1), readmission due to stress-related hypertension (n=1). None of the patients had four consecutive BP-measurements exceeding the BP threshold. Patient adherence was high; 24 patients provided ≥ 90% of the expected BP-measurements. Eight patients visited their general practitioner with concerns regarding their observed BP-values, in two leading to changes in anti-hypertensive therapy. Over 90% of patients experienced home BP-monitoring as positive and all except one recommended adding home BP-monitoring to standard care. Median intra-individual variability of systolic and diastolic BP of all patients was 12.7 mmHg and 7.4 mmHg, respectively. No significant differences in systolic BP variability or absolute values were found between patients with a post-discharge event and those without. Conclusion: Postoperative home BP-monitoring was feasible and well-accepted by CEA-patients. Future studies need to address the clinical gain of home BP-monitoring in early detection of patients at risk for postoperative hemodynamic complications

Variation in perioperative cerebral and hemodynamic monitoring during carotid endarterectomy

Background: Hemodynamic disturbances cause half of the perioperative strokes following carotid endarterectomy (CEA). Guidelines strongly recommend strict pre- and postoperative blood pressure (BP) monitoring in CEA patients, but do not provide firm practical recommendations. Although in the Netherlands 50 centres perform CEA, no national protocol on perioperative hemodynamic, and cerebral monitoring exists. To assess current monitoring policies of all Dutch CEA-centres, a national survey was conducted. Methods: Between May and July 2017 all 50 Dutch CEA-centres were invited to complete a 42-question survey addressing perioperative hemodynamic and cerebral monitoring during CEA. Nonresponders received a reminder after 1 and 2 months. By November 2017 the survey was completed by all centres. Results: Preoperative baseline BP was based on a single bilateral BP-measurement at the outpatient-clinic in the majority of centres (n = 28). In 43 centres (86%) pre-operative monitoring (transcranial Doppler (TCD, n = 6), electroencephalography (EEG, n = 11), or TCD + EEG (n = 26)) was performed as a baseline reference. Intraoperatively, large diversity for type of anaesthesia (general: 45 vs. local [LA]:5) and target systolic BP (>100 mm hg – 160 mm hg [n = 12], based on preoperative outpatient-clinic or admission BP [n = 18], other [n = 20]) was reported. Intraoperative cerebral monitoring included EEG + TCD (n = 28), EEG alone (n = 13), clinical neurological examination with LA (n = 5), near-infrared spectroscopy with stump pressure (n = 1), and none due to standard shunting (n = 3). Postoperatively, significant variation was reported in standard duration of admission at a recovery or high-care unit (range 3–48 hr, mean:12 hr), maximum accepted systolic BP (range >100 mm hg – 180 mm Hg [n = 32]), postoperative cerebral monitoring (standard TCD [n = 16], TCD on indication [n = 5] or none [n = 24]) and in timing of postoperative cerebral monitoring (range directly postoperative – 24 hr postoperative; median 3 hr). Conclusions: In Dutch centres performing CEA the perioperative hemodynamic and cerebral monitoring policies are widely diverse. Diverse policies may theoretically lead to over- or under treatment. The results of this national audit may serve as the baseline dataset for development of a standardized and detailed (inter)national protocol on perioperative hemodynamic and cerebral monitoring during CEA

Perioperative Cerebral and Hemodynamic Monitoring in Carotid Endarterectomy

Cardiovascular diseases (CVD), such as ischemic heart disease and stroke, account for one third of all deaths from all causes globally. For the majority of CVD atherosclerosis is the underlying pathology. Atherosclerosis is a systemic lipid driven inflammatory disease of the arterial vessel wall and cause narrowing/stenosis of the vessel. Significant atherosclerotic stenosis of the carotid artery is the major cause of ischemic cerebrovascular diseases (stroke/TIA). To prevent for future stroke, carotid artery revascularization by carotid endarterectomy is the recommended treatment in patients with symptomatic carotid artery stenosis. However, the benefit of carotid artery revascularization for severe carotid artery stenosis is offset by stroke due to the intervention itself. One in three of periprocedural strokes and the majority of postoperative strokes are suggested to be of hemodynamic origin, making adequate cerebral perfusion of utmost importance. This thesis evaluated the several aspects of current clinical care (part I), procedural hemodynamic monitoring (part II), and postoperative cerebral and hemodynamic (remote) monitoring (part III) in order to optimize the current periprocedural monitoring during and following carotid endarterectomy. Studies in this thesis showed that several technical improvements have led to a decrease of stroke over the past years. However, hemodynamic and cerebral monitoring before, during and after surgery of the carotid artery are widely diverse nationwide and aim for a detailed protocol to improve standardization of care. This thesis also presented evidence that (preoperative) blood pressure has a role on atherosclerotic plaque characteristics and on the development of new (silent) ischemic brain lesions. Postoperative cerebral monitoring turned out to be effective in excluding patients at risk for cerebral hyperperfusion syndrome. Finally, postoperative blood pressure monitoring techniques were evaluated in both intramural as extra mural setting. In conclusion, studies in this thesis provide evidence that blood pressure regulation and cerebral monitoring can contribute in decreasing the complication risk that is accompanied by carotid artery surgery and have a supporting role for vascular surgeon and anaesthesiologist

The ClearSight System for Postoperative Arterial Blood Pressure Monitoring After Carotid Endarterectomy: A Validation Study

BACKGROUND The majority of postoperative events in patients undergoing carotid endarterectomy (CEA) are of hemodynamic origin, requiring preventive strict postoperative arterial blood pressure (BP) control. This study aimed to assess whether BP monitoring with noninvasive beat-to-beat ClearSight finger BP (BPCS) can replace invasive beat-to-beat radial artery BP (BPRAD) in the postoperative phase. METHODS This study was a single-center clinical validation study using a prespecified study protocol. In 48 patients with symptomatic carotid artery stenosis, BPCS and BPRAD were monitored ipsilateral in a simultaneous manner during a 6-hour period on the recovery unit following CEA. Primary endpoints were accuracy and precision of BP derived by ClearSight (Edward Lifesciences, Irvine, CA) vs. the reference standard (Arbocath 20 G, Hospira, Lake Forest, IL) to investigate if BPCS is a reliable noninvasive alternative for BP monitoring postoperatively in CEA patients. Validation was guided by the standard set by the Association for Advancement of Medical Instrumentation (AAMI), considering a BP-monitor adequate when bias (precision) is <5 (8) mm Hg. Secondary endpoint was percentage under- and overtreatment, defined as exceedance of individual postoperative systolic BP threshold by BPRAD or BPCS in contrast to BPCS or BPRAD, respectively. RESULTS The bias (precision) of BPCS compared to BPRAD was −10 (13.6), 8 (7.2) and 4 (7.8) mm Hg for systolic, diastolic and mean arterial pressure (MAP), respectively. Based on BPCS, undertreatment was 5.6% and overtreatment was 2.4%; however, percentages of undertreatment quadrupled for lower systolic BP thresholds. CONCLUSIONS Noninvasive MAP, but not systolic and diastolic BP, was similar to invasive BPRAD during postoperative observation following CEA, based on AAMI criteria. However, as systolic BP is currently leading in postoperative monitoring to adjust BP therapy on, BPCS is not a reliable alternative for BPRAD

Preoperative hypertension is associated with atherosclerotic intraplaque hemorrhage in patients undergoing carotid endarterectomy

BACKGROUND AND AIMS: Both hypertension and atherosclerotic plaque characteristics such as intraplaque hemorrhage (IPH) are associated with cardiovascular events (CVE). It is unknown if hypertension is associated with IPH. Therefore, we studied if hypertension is associated with unstable atherosclerotic plaque characteristics in patients undergoing carotid endarterectomy (CEA). METHODS: Prospectively collected data of CEA-patients (2002-2014) were retrospectively analyzed. Blood pressure (BP) was the mean of 3 preoperative measurements. Preoperative hypertension was defined as systolic BP ≥ 160 mmHg. Post-CEA, carotid atherosclerotic plaques were analyzed for the presence of calcifications, collagen, smooth muscle cells, macrophages, lipid core, IPH and microvessel density. Associations between BP (systolic and diastolic), patient characteristics and carotid plaque characteristics were assessed with univariate and multivariate analyses with correction for potential confounders. Results were replicated in a cohort of patients that underwent iliofemoral endarterectomy. RESULTS: Within CEA-patients (n = 1684), 708 (42%) had preoperative hypertension. Increased systolic BP was associated with the presence of plaque calcifications (adjusted OR1.11 [95% CI 1.01-1.22], p = 0.03), macrophages (adjusted OR1.12 [1.04-1.21], p 10% of plaque area (adjusted OR1.15 [1.05-1.25], p < 0.01), IPH (adjusted OR1.12 [1.03-1.21], p = 0.01) and microvessels (adjusted beta 0.04 [0.00-0.08], p = 0.03). Increased diastolic BP was associated with macrophages (adjusted OR1.36 [1.17-1.58], p < 0.01), lipid core (adjusted OR1.29 [1.10-1.53], p < 0.01) and IPH (adjusted OR1.25 [1.07-1.46], p < 0.01) but not with microvessels nor plaque calcifications. Replication in an iliofemoral-cohort (n = 657) showed that increased diastolic BP was associated with the presence of macrophages (adjusted OR1.78 [1.13-2.91], p = 0.01), lipid core (adjusted OR1.45 [1.06-1.98], p = 0.02) and IPH (adjusted OR1.48 [1.14-1.93], p < 0.01). CONCLUSIONS: Preoperative hypertension in severely atherosclerotic patients is associated with the presence of carotid plaque macrophages, lipid core and IPH. IPH, as a plaque marker for CVE, is associated with increased systolic and diastolic BP in both the CEA and iliofemoral population

Шантарский архипелаг: основные направления природопользования

BACKGROUND: Short-acting vasopressor agents like phenylephrine or ephedrine can be used during carotid endarterectomy (CEA) to achieve adequate blood pressure (BP) to prevent periprocedural stroke by preserving the cerebral perfusion. Previous studies in healthy subjects showed that these vasopressors also affected the frontal lobe cerebral tissue oxygenation (rSO 2) with a decrease after administration of phenylephrine. This decrease is unwarranted in patients with jeopardized cerebral perfusion, like CEA patients. The study aimed to evaluate the impact of both phenylephrine and ephedrine on the rSO 2 during CEA. METHODS: In this double-blinded randomized controlled trial, 29 patients with symptomatic carotid artery stenosis underwent CEA under volatile general anesthesia in a tertiary referral medical center. Patients were preoperative allocated randomly (1:1) for receiving either phenylephrine (50 µg; n = 14) or ephedrine (5 mg; n = 15) in case intraoperative hypotension occurred, defined as a decreased mean arterial pressure (MAP) ≥ 20% compared to (awake) baseline. Intraoperative MAP was measured by an intra-arterial cannula placed in the radial artery. After administration, the MAP, cardiac output (CO), heart rate (HR), stroke volume, and rSO 2 both ipsilateral and contralateral were measured. The timeframe for data analysis was 120 s before, until 600 s after administration. RESULTS: Both phenylephrine (70 ± 9 to 101 ± 22 mmHg; p < 0.001; mean ± SD) and ephedrine (75 ± 11 mmHg to 122 ± 22 mmHg; p < 0.001) adequately restored MAP. After administration, HR did not change significantly over time, and CO increased 19% for both phenylephrine and ephedrine. rSO 2 ipsilateral and contralateral did not change significantly after administration at 300 and 600 s for either phenylephrine or ephedrine (phenylephrine 73%, 73%, 73% and 73%, 73%, 74%; ephedrine 72%, 73%, 73% and 75%, 74%, 74%). CONCLUSIONS: Within this randomized prospective study, MAP correction by either phenylephrine or ephedrine showed to be equally effective in maintaining rSO 2 in patients who underwent CEA. Clinical Trial Registration ClincalTrials.gov, NCT01451294

Intra-Operative Hypotension is a Risk Factor for Post-operative Silent Brain Ischaemia in Patients With Pre-operative Hypertension Undergoing Carotid Endarterectomy

Objective: Intra-operative haemodynamic instability during carotid endarterectomy (CEA) has been associated with an increased risk of procedural stroke. Diffusion weighted imaging (DWI) lesions have been proposed as a surrogate marker for peri-operative silent cerebral ischaemia. This study aimed to investigate the relationship between peri-operative blood pressure (BP) and presence of post-operative DWI lesions in patients undergoing CEA. Methods: A retrospective analysis was performed based on patients with symptomatic CEA included in the MRI substudy of the International Carotid Stenting Study. Relative intra-operative hypotension was defined as a decrease of intra-operative systolic BP ≥ 20% compared with pre-operative (‘baseline’) BP, absolute hypotension was defined as a drop in systolic BP < 80 mmHg. The primary endpoint was the presence of any new DWI lesions on post-operative MRI (DWI positive). The occurrence and duration of intra-operative hypotension was compared between DWI positive and DWI negative patients as was the magnitude of the difference between pre- and intra-operative BP. Results: Fifty-five patients with symptomatic CEA were included, of whom eight were DWI positive. DWI positive patients had a significantly higher baseline systolic (186 ± 31 vs. 158 ± 27 mmHg, p = .011) and diastolic BP (95 ± 15 vs. 84 ± 13 mmHg, p = .046) compared with DWI negative patients. Other pre-operative characteristics did not differ. Relative intra-operative hypotension compared with baseline occurred in 53/55 patients (median duration 34 min; range 0–174). Duration of hypotension did not differ significantly between the groups (p = .088). Mean systolic intra-operative BP compared with baseline revealed a larger drop in BP (−37 ± 29 mmHg) in DWI positive compared with DWI negative patients (−14 ± 26 mmHg, p = .024). Absolute intra-operative systolic BP values did not differ between the groups. Conclusion: In this exploratory study, high pre-operative BP and a larger drop of intra-operative BP were associated with peri-procedural cerebral ischaemia as documented with DWI. These results call for confirmation in an adequately sized prospective study, as they suggest important consequences for peri-operative haemodynamic management in carotid revascularisation

Defining the awake baseline blood pressure in patients undergoing carotid endarterectomy

BACKGROUND: To minimize the incidence of intraoperative stroke following carotid endarterectomy (CEA) under general anesthesia, blood pressure (BP) is suggested to be maintained between "awake baseline" BP and 20% above. However, there is neither a widely accepted protocol nor a definition to determine this awake BP. In this study, we analyzed the BP during hospital admission in the days before CEA and propose a definition of how to determine awake BP. METHODS: In our cohort of 1180 CEA-patients, all noninvasive BP measurements were retrospectively analyzed. BP was measured during preoperative outpatient screening (POS), the last three days before surgery at the ward and in the operating room (OR) directly before anesthesia. Primary outcome was the comparability of all these preoperative BP measurements. Secondary outcome was the comparability of preoperative BP measurements stratified for postoperative stroke within 30 days. RESULTS: POS BP (148±22/80±12 mmHg [mean arterial pressure, MAP: 103±14 mmHg]) and the BP measured on the ward 3, 2, 1 days before surgery and on the day of surgery (146±25/77±13 [MAP: 100±15]), (142±23/76±13 [MAP: 98±15]), (145±23/76±12 [MAP: 99±14]) and (144±22/75±12 mmHg [MAP: 98±14]) were comparable (all P=NS). However, BP in the OR directly before anesthesia was higher, (163±27/88±15 mmHg [MAP: 117±18mmHg]) (P<0.01 vs. all other preoperative moments). A significant higher preinduction systolic BP and MAP was observed in patients suffering a stroke within 30 days compared to patients without (P=0.03 and 0.04 respectively). CONCLUSIONS: Awake BP should be determined by averaging available BP values collected preoperatively on the ward and POS. BP measured in the OR directly before induction of anesthesia overestimates "awake" BP; and therefore, it should not be used

Transcranial Doppler 24 Hours after Carotid Endarterectomy Accurately Identifies Patients Not at Risk of Cerebral Hyperperfusion Syndrome

Objectives: Intra-operative transcranial Doppler (TCD) is the gold standard for prediction of cerebral hyperperfusion syndrome (CHS) in patients after carotid endarterectomy (CEA) under general anaesthesia. However, post-operative cerebral perfusion patterns may result in a shift in risk assessment for CHS. This is a study of the predictive value of additional post-operative TCD measurements for prediction of CHS after CEA. Methods: This was a retrospective analysis of prospectively collected data in patients undergoing CEA with available intra- and post-operative TCD measurements between 2011 and 2016. The mean blood flow velocity in the middle cerebral artery (MCAVmean) was measured pre-operatively, intra-operatively, and post-operatively at two and 24 h. Intra-operative MCAVmean increase was compared with MCAVmean increase two and 24 h post-operatively in relation to CHS. Cerebral hyperperfusion (CH) was defined as MCAVmean increase ≥ 100%, and CHS as CH with the presence of headache or neurological symptoms. Positive (PPV) and negative predictive values (NPV) of TCD measurements were calculated to predict CHS. Results: Of 257 CEA patients, 25 (9.7%) had CH intra-operatively, 45 (17.5%) 2 h post-operatively, and 34 (13.2%) 24 h post-operatively. Of nine patients (3.5%) who developed CHS, intra-operative CH was diagnosed in two and post-operative CH in eight (after 2 h [n = 5] or after 24 h [n = 6]). This resulted in a PPV of 8%, 11%, and 18%, and a NPV of 97%, 98%, and 99% for intra-operative, 2 h and 24 h post-operative TCD, respectively. Conclusions: TCD measurement of the MCAVmean 24 h after CEA under general anaesthesia is most accurate to identify patients who are not at risk of CHS