High-Frequency versus Low-Frequency Spinal Cord Stimulation in Treatment of Chronic Limb-Threatening Ischemia: Short-Term Results of a Randomized Trial.

INTRODUCTION: The objective of the study is to determine if high-frequency (1 kHz) spinal cord stimulation (SCS) is better than low-frequency SCS for pain relief in chronic limb-threatening ischemia (CLTI). METHODS: HEAL-SCS trial was designed as an open-label, parallel-group, single-center randomized study with a 1:1 allocation ratio. The trial was conducted in Meshalkin National Medical Research Center between August 2018 and February 2020. Total 56 patients underwent screening, 50 were enrolled, 6 were rejected. The participants were randomized into 2 cohorts of 25 patients each by an external coordinator using an online tool. A neurosurgeon and a vascular surgeon both examined all patients and estimated the pain intensity using visual analog scale (VAS), quality of life with short-form-36 health survey (SF-36), and functional status by walking impairment questionnaire (WIQ) at 3 and 12 months. Tissue perfusion was evaluated for 34 patients using transcutaneous oxygen tension measurement (TcPO2) at baseline and in 12 months. RESULTS: All 50 patients (84% men, median age 66.5 y.o) were available for primary outcome assessment 3 and 12 months after implantation. Intention-to-treat analysis demonstrated comparative advantage of HF-SCS over LF-SCS at 3 months with mean VAS score 2.8 (95% CI, 2.4; 3.2) and 3.3 (95% CI, 3.0; 3.6), respectively (p = 0.031). Clinical superiority of HF-SCS persisted at 12-month follow-up (p < 0.001). HF-SCS produced significantly greater pain relief by WIQ at 3 (p < 0.001) and 12 months (p = 0.009). Despite stair-climbing ability was better in HF-SCS group (p = 0.02), no significant difference between groups was found at 1-year post-op in terms of speed (p = 0.92) and distance scores (p = 0.68). Accordingly, the general and mental health domains of SF-36 were significantly better in HF-SCS at 12 months. Despite a tendency toward better resting oxygen pressure in HF-SCS group, there was no intergroup difference by TcPO2 (p = 0.076). Only 1 patient (2%) required above-the-knee amputation at 10 months after LF-SCS implantation. CONCLUSION: High-frequency SCS provides better pain relief, life quality, and functional performance in patients with CLTI during short-term follow-up. The lack of perfusion difference between high-frequency and conventional SCS requires further examination to the possible long-term advantages of the method.

Brain Oxygen Supply in Older Adults During Coronary Artery Bypass Grafting.

OBJECTIVES: To evaluate the dynamics of the cerebral oxygen supply in patients aged ≥65 years, during coronary artery bypass grafting (CABG), and to test the hypothesis that lower intraoperative brain oxygen saturation is associated with postoperative neurological complications. DESIGN: Prospective cohort study. SETTING: The E. Meshalkin National Medical Research Center of the Ministry of Health of the Russian Federation, Novosibirsk, Russia. PARTICIPANTS: The study comprised 200 elderly patients who underwent CABG between April, 2018 and November, 2019. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The regional hemoglobin oxygen saturation (rSO2, %) of the right and left brain hemispheres were assessed during the intraoperative period using bilateral near-infrared spectroscopy. Furthermore, neurological complications during hospitalization were evaluated. At the anesthesia induction stage, the average levels of rSO2 for the right and left hemispheres were within 65% and did not differ significantly at any stage of CABG (p>0.05). The risk of neurological complications was associated with rSO2 decrease during cardiopulmonary bypass (CPB). An increased risk was associated with rSO2 decrease by 20% or more during CPB, relative to the stage of anesthesia induction, which was observed in 19% of patients. CONCLUSIONS: In elderly patients, the decrease in rSO2 during CPB is associated with an increased risk of neurological complications during hospitalization. This risk increases with a decrease in rSO2 by 20% or more during CPB relative to the stage of anesthesia induction, by a 5-fold and 7-fold for the left and right hemispheres, respectively.

Long-term health-related quality of life after surgery in patients with chronic thromboembolic pulmonary hypertension.

PURPOSE: To assess the dynamic of various health-related quality of life (HRQoL) parameters 3 years after pulmonary thromboendarterectomy (PTE), and to identify factors affecting HRQoL parameters in patients with chronic thromboembolic pulmonary hypertension (CTEPH) in the long-term follow-up after surgery. METHODS: This prospective cohort study included 128 patients with CTEPH before and after the PTE (3 year follow-up). The HRQoL was examined using the Short-Form 36 Health Survey Questionnaire (SF-36). RESULTS: In patients with CTEPH 3 years after PTE, a significant improvement in all the HRQoL parameters. The summary indicators of the physical and mental components of health remained at the same level as 1 year after the PTE and did not exceed 50 points. The residual pulmonary hypertension was a leading factor limiting parameters of physical and mental health 3 years after a PTE. In addition, the parameters of physical activity were adversely affected by age and the age-adjusted Charlson Comorbidity Index. CONCLUSIONS: In the study group of patients with CTEPH, PTE contributes to a significant improvement in all HRQoL parameters, which observed both 1 year and 3 years after surgery. The leading factor adversely affecting the physical and emotional components of health in the long-term period after PTE was residual pulmonary hypertension recorded in the early postoperative period. In addition, some physical HRQoL parameters are affected by age and age-adjusted Charlson Comorbidity Index.

The Clinical Outcomes in Patients with Critical Limb Ischemia One Year after Spinal Cord Stimulation.

BACKGROUND: The aim of this study was to evaluate the long-term outcomes of spinal cord stimulation in patients with critical limb ischemia and to test the hypothesis that the dynamics of clinical changes one year after therapy depend both on the clinical determinants associated with the underlying disease and on factors related to systemic atherosclerosis. METHODS: This prospective cohort study included 56 patients with critical limb ischemia. All patients before and after spinal cord stimulation were examined in terms of the dynamics of their clinical changes using the Rutherford scale and transcutaneous oxygen tension (TcPO2, mm Hg) in the affected foot. The active orthostatic test was used to assess the functional state of peripheral perfusion. RESULTS: One year after spinal cord stimulation, 74% of patients showed positive clinical outcomes. No changes were observed in 9.3% of patients, whereas adverse clinical outcomes were revealed in 16.7% of cases. The TcPO2 values were significantly reduced before spinal cord stimulation: 10.5 (6.4-16.0) mm Hg. The functional status of the peripheral microvasculature was also disturbed. One year after therapy, TcPO2 significantly increased and the adaptive mechanisms of the microvasculature were improved in more than 70% of patients. Logistic regression analysis showed that the initially low TcPO2 values (<10 mm Hg) with a lack of gain in TcPO2 during the orthostatic test are associated with the negative clinical outcomes after spinal cord stimulation. The gain in TcPO2 during the orthostatic test to >10 mm Hg is associated with the positive clinical outcomes after spinal cord stimulation. The age-adjusted Charlson Comorbidity Index >5 and duration of critical ischemic symptoms also had a negative effect on the clinical outcomes after spinal cord stimulation. CONCLUSIONS: The positive clinical outcomes were revealed in most patients with critical limb ischemia one year after spinal cord stimulation. The low values of peripheral tissue metabolism with the disturbed functional status of the microvasculature are associated with the negative clinical outcome. The patients with baseline TcPO2 <10 mm Hg can recover if they still have a sufficient microcirculatory reserve capacity. Duration of critical ischemic symptoms and high comorbidity burden with allowance for age are negative factors affecting the clinical outcome.

Health-related quality of life one year after surgical treatment of the type I chronic aortic dissection.

BACKGROUND: The purpose of our study was to assess the health-related quality of life (HRQoL) in patients with type I chronic aortic dissection before and one year after prosthetics of the aorta, and to test the hypothesis that long-term postoperative parameters of HRQoL are affected by clinical determinants related to the underlying disease, intraoperative characteristics, and complications of the early postoperative period. METHODS: This prospective cohort study included 82 patients with type I chronic aortic dissection. HRQoL parameters were examined using the Short-Form 36 Health Survey Questionnaire before and one year after surgery. RESULTS: Patients with aortic dissection one year after surgery demonstrated an improvement in many HRQoL parameters, including two summary measures of the questionnaire - Physical component summary (PCS) and Mental component summary (MCS). A lower level of PCS and MCS at the preoperative stage significantly predicted lower values of these indices for a long time after aortic prosthetics. The neurological complications in the early postoperative period were the factor affecting the MCS after surgery. Moreover, the neurological complications and the presence of coronary artery disease increased the risk of the adverse outcomes, including aortic related death and significant decrease of MCS or aortic related death and significant decrease of PCS one year after the operation, respectively. CONCLUSIONS: Surgical treatment in patients with type I chronic aortic dissection leads to an increase of many HRQoL parameters. Factors affecting MCS and PCS one year after surgery included the neurological complications and lower level of the MCS and PCS at the preoperative stage. Furthermore, the neurological complications and the presence of coronary artery disease increased the risk of the combined endpoints - aortic related death and significant decrease of MCS or aortic related death and significant decrease of PCS one year after the operation, respectively.

Determinants of Health-Related Quality of Life 1 Year after Pulmonary Thromboendarterectomy.

BACKGROUND: Pulmonary thromboendarterectomy (PTE) is a recognized treatment for patients with chronic thromboembolic pulmonary hypertension (CTEPH), with good long-term hemodynamic results. The aim of this study was to test the hypothesis that the dynamics of health-related quality of life (QoL), 1 year after PTE, depend both on the clinical determinants associated with the underlying disease and the adverse events occurring in the early postoperative period. METHODS: This prospective cohort study included 136 patients with CTEPH. All patients before and after PTE (1-year follow-up) were examined in terms of QoL, by using the Short Form 36 Health Survey Questionnaire. RESULTS: One year after PTE, a significant improvement in the QoL of patients was observed in all subscales of the Short Form 36 Health Survey Questionnaire, except in the general health scale. Multivariate analysis showed that the predictors adversely affecting the dynamics of QoL after PTE were the presence of comorbidities (such as chronic obstructive pulmonary disease [COPD] and coronary artery disease) and early postoperative complications (specific ones for this category of patients are residual pulmonary hypertension and neurological complications, and nonspecific ones are atrial fibrillation and heart failure). CONCLUSIONS: The determinants that affect the dynamics of QoL 1 year after PTE in patients with CTEPH were the presence of comorbidities (COPD and coronary artery disease) and adverse events in the early postoperative period (residual pulmonary hypertension, neurological complications, atrial fibrillation, and heart failure).

Chronic Lung Disease and Mortality after Cardiac Surgery: A Prospective Cohort Study.

OBJECTIVE: To investigate the 1-year survival in cardiac surgical patients with lung disease, including previously undiagnosed cases. DESIGN: Prospective cohort study. SETTING: Tertiary hospital. PARTICIPANTS: Patients scheduled for elective coronary artery bypass graft (CABG) surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Pulmonary function tests (PFTs) were performed in 454 patients before surgery. Abnormal respiratory patterns were defined as follows: obstructive (forced expiratory volume in 1 second/forced vital capacity <0.70), restrictive (forced expiratory volume in 1 second/forced vital capacity ≥0.70 and forced vital capacity <80% of predicted), and mixed. Overall 1-year mortality was 3.3%. Among 31 patients with documented chronic obstructive pulmonary disease (COPD), mortality was 9.6%, hazard ratio (HR) 1.28, 95% confidence interval (CI) 1.02-12.80, p = 0.04. Of 423 patients without history of COPD, 57 obstructive, 46 restrictive, and 4 mixed abnormal patterns were identified. Of a total of 72 with obstructive lung disease confirmed by PFT (ie, 15 of COPD patients and 57 newly identified cases), 6.9% died, HR 2.75, 95% CI 0.98-8.07, p = 0.06. When combined with cases of COPD where a respiratory abnormality was confirmed (26 patients), newly diagnosed obstructive lung disease (57 patients) was significantly associated with 1-year mortality, HR 4.13, 95% CI 1.50-11.42, p = 0.006. The adjustment for EuroSCORE II did not change the results. CONCLUSIONS: Combination of confirmed preexisting lung disease and newly diagnosed cases provides a clear link to mid-term mortality.

Factors affecting the quality of life before and after surgery in patients with chronic thromboembolic pulmonary hypertension.

PURPOSE: To test the hypothesis that quality of life (QoL) parameters before surgery in patients with chronic thromboembolic pulmonary hypertension (CTEPH) are influenced by clinical determinants related to the underlying disease and to examine QoL parameters affected in the long-term after the operation by complications presenting in the early postoperative period. METHODS: This prospective cohort study included 128 patients who presented with CTEPH before and after pulmonary thromboendarterectomy (PTE; 1-year follow-up). All patients were examined regarding QoL using the Short-Form 36 Health Survey Questionnaire (SF-36). RESULTS: In patients with CTEPH, PTE provided immediate improvement in terms of pulmonary hemodynamic parameters and favorable effects on long-term outcome, including QoL 1 year after surgery. Multivariate analysis showed that systolic pulmonary arterial pressure, right ventricular ejection fraction, and the presence of coronary artery disease and chronic obstructive pulmonary disease (COPD) were independent factors affecting QoL on several SF-36 subscales in patients with CTEPH prior to surgery. The factors that affect patient QoL 1 year after surgery on some SF-36 subscales included the presence of coronary artery disease, COPD, heart failure, residual pulmonary hypertension, and prolonged ventilation, neurological complications in the early postoperative period of PTE. CONCLUSIONS: Surgical treatment for CTEPH leads to an increase in QoL in all SF-36 subscales, excluding general health perceptions. Factors affecting QoL in patients with CTEPH included severity of pulmonary arterial hypertension, comorbidity, and complications in the early postoperative period after PTE, such as heart failure, neurologic problems, residual pulmonary hypertension, and prolonged ventilation.

Prevalence and Implications of Abnormal Respiratory Patterns in Cardiac Surgery: A Prospective Cohort Study.

OBJECTIVE: To investigate the prevalence and impact of abnormal respiratory patterns in cardiac surgery patients. DESIGN: Prospective cohort study. SETTING: Tertiary hospital. PARTICIPANTS: Patients scheduled for elective coronary artery bypass graft surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Pulmonary function tests were performed in 454 patients before surgery. Abnormal respiratory patterns were defined as follows: obstructive (forced expiratory volume in 1 s [FEV1]/forced vital capacity [FVC]<0.70), restrictive (FEV1/FVC≥0.70 and FVC<80% of predicted), and mixed (FEV1/FVC<0.70 and both FEV1 and FVC<80% of predicted). Of the 31 patients with a history of chronic obstructive pulmonary disease, no abnormal respiratory pattern was confirmed in 5. Of the 423 patients without a history of lung disease, the authors newly identified 57 obstructive, 46 restrictive, and 4 mixed patterns. Therefore, lung disease was reclassified in 24.7% of cases. Independent predictors of obstructive pattern were age, male sex, history of smoking, and chronic obstructive pulmonary disease. Obstructive lung disease was associated with 16 hours or longer ventilation. A reduced FEV1 was associated with a likelihood of atrial fibrillation (1-L decrement, odds ratio: 1.38, 95% confidence interval: 1.01-to-1.90, p = 0.04) and hospitalization time (regression coefficient: 1.23, 95% confidence interval: 0.54-to-1.91, p<0.001). CONCLUSIONS: Abnormal respiratory patterns are common and often underdiagnosed in the cardiac surgery setting. Pulmonary function tests help reveal patients at risk of complications and may provide an opportunity for intervention.

Deep Hypothermic Circulatory Arrest vs. Antegrade Cerebral Perfusion in Cerebral Protection during the Surgical Treatment of Chronic Dissection of the Ascending and Arch Aorta.

Circulatory arrest during aortic surgery presents a risk of neurological complications. The present study aimed to investigate the effectiveness of deep hypothermic circulatory arrest (DHCA) vs. antegrade cerebral perfusion (ACP) in cerebral protection during the surgical treatment of chronic dissection of the ascending and arch aorta and to assess the quality-of-life (QoL) in the long-term postoperative period with respect to the used cerebral protection method. In a prospective, randomized study, 58 patients with chronic type I aortic dissection who underwent ascending aorta and aortic arch replacement surgery were included. Patients were allocated in two groups: 29 patients who underwent surgery under moderate hypothermia (24°C) combined with ACP and 29 patients who underwent surgery under DHCA (18°C) with craniocerebral hypothermia. The regional hemoglobin oxygen saturation (rSO2, %) were compared during surgery, neurological complications were analyzed during the early postoperative period, QoL was compared in the long-term postoperative period (1-year follow-up). During the early postoperative period, 37.9% of patients in the DHCA group exhibited neurological complications, compared with 13.8% of those in the ACP group (p < .05). The risk of neurological complications in the early postoperative period was dependent on the extent of rSO2 decrease during circulatory arrest. In the ACP group, rSO2 decreased by ≤17% from baseline during circulatory arrest. In the DHCA group, a more profound decrease in rSO2 (>30%) was recorded (p < .05). QoL in the long-term period after surgery improved, but it was not dependent on the cerebral protection method used during surgery. ACP during aortic replacement demonstrated the most advanced properties of cerebral protection that can be evidenced by a lesser degree of neurological complications, compared with patients who underwent surgery under conditions of DHCA. QoL after surgery was not dependent on the cerebral protection method used during surgery.

Efficiency of Various Cerebral Protection Techniques Used during the Surgical Treatment of Chronic Pulmonary Thromboembolism.

Circulatory arrest during pulmonary thromboendarterectomy (PTE) for chronic pulmonary embolism leads to an increased risk of cerebral ischemia and neurological complications. This study aimed to assess the efficacy of various cerebral protection techniques used during the surgical treatment of chronic pulmonary thromboembolism. We prospectively studied 61 patients with chronic pulmonary thromboembolism who underwent PTE. We compared the dynamics of cerebral oxygen saturation (rSO2, %) during the surgical treatment and analyzed neurological complications during the early postoperative period in two groups of patients: 30 patients who underwent surgery under conditions of moderate hypothermia (23°C-24°C) combined with antegrade unilateral cerebral perfusion (ACP group) and 31 patients who underwent thromboendarterectomy under deep hypothermic circulatory arrest (18°C, DHCA group) combined with craniocerebral hypothermia. In the ACP group, regional rSO2 decreased by less than 20% from baseline during the course of PTE. In the DHCA group, a more profound reduction of cerebral oxygen supply (by >30% from baseline) was recorded compared with the ACP group (p < .05). During the early postoperative period, 29% of patients in the DHCA group exhibited neurological complications, compared with only 7% of patients from the ACP group. The results of logistic regression analysis indicated that the risk of progressive neurological deficit depended on the duration of the intraoperative period when the absolute values of regional rSO2 were <40%. The method with the best adjustment to human physiology in patients with chronic pulmonary thromboembolism was antegrade cerebral perfusion. This method provides a smaller decrease in cerebral oxygen supply during thromboendarterectomy and significantly reduces the risk of ischemia and neurological complications in the early postoperative period.