Diabetes- versus smoking-related thrombo-inflammation in peripheral artery disease.

Peripheral artery disease (PAD) is a major health problem with increased cardiovascular mortality, morbidity and disabling critical limb threatening ischemia (CLTI) and amputation. Diabetes mellitus (DM) and cigarette smoke are the main risk factors for the development of PAD. Although diabetes related PAD shows an accelerated course with worse outcome regarding complications, mortality and amputations compared with non-diabetic patients, current medical treatment does not make this distinction and includes standard antiplatelet and lipid lowering drugs for all patients with PAD. In this review we discuss the pathophysiologic mechanisms of PAD, with focus on differences in thrombo-inflammatory processes between diabetes-related and smoking-related PAD, and hypothesize on possible mechanisms for the progressive course of PAD in DM. Furthermore, we comment on current medical treatment and speculate on alternative medical drug options for patients with PAD and DM.

CYP2C19 genotype-guided antithrombotic treatment versus conventional clopidogrel therapy in peripheral arterial disease: study design of a randomized controlled trial (GENPAD).

BACKGROUND: Clopidogrel is recommended in international guidelines to prevent arterial thrombotic events in patients with peripheral arterial disease (PAD). Clopidogrel itself is inactive and metabolism is dependent on the CYP2C19 enzyme. About 30% of Caucasian PAD patients receiving clopidogrel carry 1 or 2 CYP2C19 loss-of-function allele(s) and do not or to a limited extent convert the prodrug into its active metabolite. As a result, platelet inhibition may be inadequate which could lead to an increased risk of adverse clinical events related to arterial thrombosis. A CYP2C19 genotype-guided antithrombotic treatment might be beneficial for PAD patients. METHODS: GENPAD is a multicenter randomized controlled trial involving 2,276 PAD patients with an indication for clopidogrel monotherapy. Patients with a separate indication for dual antiplatelet therapy or stronger antithrombotic therapy are not eligible for study participation. Patients randomized to the control group will receive clopidogrel 75 mg once daily without pharmacogenetic guidance. Patients randomized to the intervention group will be tested for carriage of CYP2C19 *2 and *3 loss-of-function alleles, followed by a genotype-guided antithrombotic treatment with either clopidogrel 75 mg once daily for normal metabolizers, clopidogrel 150 mg once daily for intermediate metabolizers, or acetylsalicylic acid 80 mg once daily plus rivaroxaban 2.5 mg twice daily for poor metabolizers. The primary outcome is a composite of myocardial infarction, ischemic stroke, cardiovascular death, acute or chronic limb ischemia, peripheral vascular interventions, or death. The secondary outcomes are the individual elements of the primary composite outcome and clinically relevant bleeding complications. CONCLUSION: The aim of the GENPAD study is to evaluate the efficacy, safety, and cost-effectiveness of a genotype-guided antithrombotic treatment strategy compared to conventional clopidogrel treatment in PAD patients.

Sustained inflammation, coagulation activation and elevated endothelin-1 levels without macrovascular dysfunction at 3 months after COVID-19.

INTRODUCTION: Endothelial damage and thrombosis caused by COVID-19 may imperil cardiovascular health. More than a year since the WHO declared COVID-19 pandemic, information on its effects beyond the acute phase is lacking. We investigate endothelial dysfunction, coagulation and inflammation, 3 months post-COVID-19. MATERIALS AND METHODS: A cohort study was conducted including 203 patients with prior COVID-19. Macrovascular dysfunction was assessed by measuring the carotid artery diameter in response to hand immersion in ice-water. A historic cohort of 312 subjects served as controls. Propensity score matching corrected for baseline differences. Plasma concentrations of endothelin-1 were measured in patients post-COVID-19, during the acute phase, and in matched controls. Coagulation enzyme:inhibitor complexes and inflammatory cytokines were studied. RESULTS AND CONCLUSIONS: The prevalence of macrovascular dysfunction did not differ between the COVID-19 (18.6%) and the historic cohort (22.5%, RD -4%, 95%CI: -15-7, p = 0.49). Endothelin-1 levels were significantly higher in acute COVID-19 (1.67 ± 0.64 pg/mL) as compared to controls (1.24 ± 0.37, p < 0.001), and further elevated 3 months post-COVID-19 (2.74 ± 1.81, p < 0.001). Thrombin:antithrombin(AT) was high in 48.3%. Markers of contact activation were increased in 16-30%. FVIIa:AT (35%) and Von Willebrand Factor:antigen (80.8%) were elevated. Inflammatory cytokine levels were high in a majority: interleukin(IL)-18 (73.9%), IL-6 (47.7%), and IL-1ra (48.9%). At 3 months after acute COVID-19 there was no indication of macrovascular dysfunction; there was evidence, however, of sustained endothelial cell involvement, coagulation activity and inflammation. Our data highlight the importance of further studies on SARS-CoV-2 related vascular inflammation and thrombosis, as well as longer follow-up in recovered patients.

Remote ischaemic preconditioning does not modulate the systemic inflammatory response or renal tubular stress biomarkers after endotoxaemia in healthy human volunteers: a single-centre, mechanistic, randomised controlled trial.

BACKGROUND: Remote ischaemic preconditioning (RIPC) consists of repeated cycles of limb ischaemia and reperfusion, which may reduce perioperative myocardial ischaemic damage and kidney injury. We hypothesised that RIPC may be beneficial by attenuating the systemic inflammatory response. We investigated whether RIPC affects the response in humans to bacterial endotoxin (lipopolysaccharide [LPS]) by measuring plasma cytokines and renal cell-cycle arrest mediators, which reflect renal tubular stress. METHODS: Healthy male volunteers were randomised to receive either daily RIPC for 6 consecutive days (RIPCmultiple, n=10) plus RIPC during the 40 min preceding i.v. LPS (2 ng kg-1), RIPC only during the 40 min before LPS (RIPCsingle, n=10), or no RIPC preceding LPS (control, n=10). As a surrogate marker of renal tubular stress, the product of urinary concentrations of two cell-cycle arrest markers was calculated (tissue inhibitor of metalloproteinases-2 [TIMP2]*insulin-like growth factor binding protein-7 [IGFBP7]). Data are presented as median (inter-quartile range). RESULTS: In both RIPC groups, RIPC alone increased [TIMP2]*[IGFBP7]. LPS administration resulted in fever, flu-like symptoms, and haemodynamic alterations. Plasma cytokine concentrations increased profoundly during endotoxaemia (control group: tumor necrosis factor alpha [TNF-α] from 14 [9-16] pg ml-1 at baseline to 480 [284-709] pg ml-1 at 1.5 h after LPS; interleukin-6 [IL-6] from 4 [4-4] pg ml-1 at baseline to 659 [505-1018] pg ml-1 at 2 h after LPS). LPS administration also increased urinary [TIMP2[*[IGFBP7]. RIPC had no effect on LPS-induced cytokine release or [TIMP2]*[IGFBP7]. CONCLUSIONS: RIPC neither modulated systemic cytokine release nor attenuated inflammation-induced tubular stress after LPS. However, RIPC alone induced renal markers of cell-cycle arrest. CLINICAL TRIAL REGISTRATION: NCT02602977.

Deep neuromuscular blockade improves surgical conditions during low-pressure pneumoperitoneum laparoscopic donor nephrectomy.

BACKGROUND: Evidence indicates that low-pressure pneumoperitoneum (PNP) reduces postoperative pain and analgesic consumption. A lower insufflation pressure may hamper visibility and working space. The aim of the study is to investigate whether deep neuromuscular blockade (NMB) improves surgical conditions during low-pressure PNP. METHODS: This study was a blinded randomized controlled multicenter trial. 34 kidney donors scheduled for laparoscopic donor nephrectomy randomly received low-pressure PNP (6 mmHg) with either deep (PTC 1-5) or moderate NMB (TOF 0-1). In case of insufficient surgical conditions, the insufflation pressure was increased stepwise. Surgical conditions were rated by the Leiden-Surgical Rating Scale (L-SRS) ranging from 1 (extremely poor) to 5 (optimal). RESULTS: Mean surgical conditions were significantly better for patients allocated to a deep NMB (SRS 4.5 versus 4.0; p < 0.01). The final insufflation pressure was 7.7 mmHg in patients with deep NMB as compared to 9.1 mmHg with moderate NMB (p = 0.19). The cumulative opiate consumption during the first 48 h was significantly lower in patients receiving deep NMB, while postoperative pain scores were similar. In four patients allocated to a moderate NMB, a significant intraoperative complication occurred, and in two of these patients a conversion to an open procedure was required. CONCLUSIONS: Our data show that deep NMB facilitates the use of low-pressure PNP during laparoscopic donor nephrectomy by improving the quality of the surgical field. The relatively high incidence of intraoperative complications indicates that the use of low pressure with moderate NMB may compromise safety during LDN. Clinicaltrials.gov identifier: NCT 02602964.

Deep neuromuscular block to optimize surgical space conditions during laparoscopic surgery: a systematic review and meta-analysis.

Neuromuscular block (NMB) is frequently used in abdominal surgery to improve surgical conditions by relaxation of the abdominal wall and prevention of sudden muscle contractions. The evidence supporting routine use of deep NMB is still under debate. We aimed to provide evidence for the superiority of routine use of deep NMB during laparoscopic surgery. We performed a systematic review and meta-analysis of studies comparing the influence of deep vs moderate NMB during laparoscopic procedures on surgical space conditions and clinical outcomes. Trials were identified from Medline, Embase, and Central databases from inception to December 2016. We included randomized trials, crossover studies, and cohort studies. Our search yielded 12 studies on the effect of deep NMB on the surgical space conditions. Deep NMB during laparoscopic surgeries improves the surgical space conditions when compared with moderate NMB, with a mean difference of 0.65 (95% confidence interval (CI): 0.47-0.83) on a scale of 1-5, and it facilitates the use of low-pressure pneumoperitoneum. Furthermore, deep NMB reduces postoperative pain scores in the postanaesthesia care unit, with a mean difference of - 0.52 (95% CI: -0.71 to - 0.32). Deep NMB improves surgical space conditions during laparoscopic surgery and reduces postoperative pain scores in the postanaesthesia care unit. Whether this leads to fewer intraoperative complications, an improved quality of recovery, or both after laparoscopic surgery should be pursued in future studies. The review methodology was specified in advance and registered at Prospero on July 27, 2016, registration number CRD42016042144.

Remote Ischemic Preconditioning To Reduce Contrast-Induced Nephropathy: A Randomized Controlled Trial.

BACKGROUND: Despite the increasing use of pre- and post-hydration protocols and low osmolar instead of high osmolar iodine containing contrast media, the incidence of contrast induced nephropathy (CIN) is still significant. There is evidence that contrast media cause ischemia reperfusion injury of the renal medulla. Remote ischemic preconditioning (RIPC) is a non-invasive, safe, and low cost method to reduce ischemia reperfusion injury. The aim of this study is to investigate whether RIPC, as an adjunct to standard preventive measures, reduces contrast induced acute kidney injury in patients at risk of CIN. METHODS: The RIPCIN study is a multicenter, single blinded, randomized controlled trial in which 76 patients at risk of CIN received standard hydration combined with RIPC or hydration with sham preconditioning. RIPC was applied by four cycles of 5 min ischemia and 5 min reperfusion of the forearm. The primary outcome measure was the change in serum creatinine from baseline to 48 to 72 hours after contrast administration. RESULTS: With regard to the primary endpoint, no significant effect of RIPC was found. CIN occurred in four patients (2 sham and 2 RIPC). A pre-defined subgroup analysis of patients with a Mehran risk score ≥11, showed a significantly reduced change in serum creatinine from baseline to 48 to 72 hours in patients allocated to the RIPC group (Δ creatinine -3.3 ± 9.8 µmol/L) compared with the sham group (Δ creatinine +17.8 ± 20.1 µmol/L). CONCLUSION: RIPC, as an adjunct to standard preventive measures, does not improve serum creatinine levels after contrast administration in patients at risk of CIN according to the Dutch guideline. However, the present data indicate that RIPC might have beneficial effects in patients at a high or very high risk of CIN (Mehran score ≥ 11). The RIPCIN study is registered at: http://www.controlled-trials.com/ISRCTN76496973.

Components of pain assessment after laparoscopic donor nephrectomy.

BACKGROUND: Pain after laparoscopic surgery can be divided into three components: incisional or superficial wound pain, deep intra-abdominal pain and referred shoulder pain. Better understanding and adequate assessment of post-operative pain may be an important clue to the optimisation of recovery after laparoscopic surgery. Therefore, we performed a components of pain assessment after laparoscopic donor nephrectomy. METHODS: Twenty patients who underwent a laparoscopic donor nephrectomy were included in this prospective study. Pain was subdivided into three components: superficial wound pain, deep intra-abdominal pain and referred shoulder pain, and for each component a numeric rating scale (from 0 to 10) was obtained at 1, 24 and 48 h after surgery. RESULTS: Repeated measurements analysis of variance showed that during the first 48 h after surgery, the superficial wound and deep intra-abdominal pain components were significantly higher as compared with the referred shoulder pain component. Although the deep intra-abdominal pain component was slightly higher as compared with superficial wound pain, this difference was not significant (P = 0.097). Further assessment of superficial wound pain showed that the Pfannenstiel incision was the most significant determinant of this component of pain (P = 0.004), whereas deep intra-abdominal pain was significantly higher at the ipsilateral side of the abdomen (P = 0.015). DISCUSSION: The components of pain assessment revealed that pain related to the Pfannenstiel incision and the deep intra-abdominal pain component are the most important determinants of pain after laparoscopic donor nephrectomy. Further improvement of the management of post-operative pain should focus on these components of pain.

Low-pressure pneumoperitoneum during laparoscopic donor nephrectomy to optimize live donors' comfort.

Nowadays, laparoscopic donor nephrectomy (LDN) has become the gold standard to procure live donor kidneys. As the relationship between donor and recipient loosens, it becomes of even greater importance to optimize safety and comfort of the surgical procedure. Low-pressure pneumoperitoneum has been shown to reduce pain scores after laparoscopic cholecystectomy. Live kidney donors may also benefit from the use of low pressure during LDN. To evaluate feasibility and efficacy to reduce post-operative pain, we performed a randomized blinded study. Twenty donors were randomly assigned to standard (14 mmHg) or low (7 mmHg) pressure during LDN. One conversion from low to standard pressure was indicated by protocol due to lack of progression. Intention-to-treat analysis showed that low pressure resulted in a significantly longer skin-to-skin time (149 ± 86 vs. 111 ± 19 min), higher urine output during pneumoperitoneum (23 ± 35 vs. 11 ± 20 mL/h), lower cumulative overall pain score after 72 h (9.4 ± 3.2 vs. 13.5 ± 4.5), lower deep intra-abdominal pain score (11 ± 3.3 vs. 7.5 ± 3.1), and a lower cumulative overall referred pain score (1.8 ± 1.9 vs. 4.2 ± 3). Donor serum creatinine levels, complications, and quality of life dimensions were not significantly different. Our data show that low-pressure pneumoperitoneum during LDN is feasible and may contribute to increase live donors' comfort during the early post-operative phase.

Poor early graft function impairs long-term outcome in living donor kidney transplantation.

BACKGROUND: Poor early graft function (EGF) after living donor kidney transplantation (LDKT) has been found to decrease rejection-free graft survival rates. However, its influence on long-term graft survival remains inconclusive. METHODS: Data were collected on 472 adult LDKTs performed between July 1996 and February 2010. Poor EGF was defined as the occurrence of delayed or slow graft function. Slow function was defined as serum creatinine above 3.0 mg/dL at postoperative day 5 without dialysis. RESULTS: The incidence of slow and delayed graft function was 9.3 and 4.4%, respectively. Recipient overweight, pretransplant dialysis and warm ischemia were identified as risk factors for the occurrence of poor EGF. The rejection-free survival was worse for poor EGF as compared to immediate graft function with an adjusted hazard ratio (HR) of 6.189 (95% CI 4.075-9.399; p < 0.001). Long-term graft survival was impaired in the poor EGF group with an adjusted HR of 4.206 (95% CI 1.839-9.621; p = 0.001). CONCLUSIONS: Poor EGF occurs in 13.7% of living donor kidney allograft recipients. Both, rejection-free and long-term graft survivals are significantly lower in patients with poor EGF as compared to patients with immediate graft function. These results underline the clinical relevance of poor EGF as phenomenon after LDKT.

Deleterious influence of prolonged warm ischemia in living donor kidney transplantation.

BACKGROUND: Recent studies investigating early graft function (EGF) after living donor kidney transplantation (LDKT) identified prolonged warm ischemia time (WIT) as a risk factor for the occurrence of poor EGF. The latter is associated with long-term graft loss; therefore the question arises whether prolonged WIT affects long-term outcomes in LDKT. METHODS: Data were collected on 472 consecutive adult LDKTs. Patients were divided according to the total WIT into 3 groups with short (<30 minutes), intermediate (30-45 minutes), or prolonged (>45 minutes) WIT. RESULTS: Of all patients, 193 (40.9%) experienced short, 249 (52.8%) intermediate, and 30 (6.4%) prolonged WIT. Prolonged WIT was a significant risk factor for the occurrence of poor EGF with an adjusted odds ratio of 4.252 (95% confidence interval [CI), 1.914 -9.447). Long-term graft survival was impaired in patients with prolonged WIT, with an adjusted hazard ratio of 3.163 (95% CI, 1.202-8.321). Multivariate analysis revealed determinants of prolonged WIT, including laparoscopic procurement, recipient overweight, right donor kidney, and multiple renal arteries. CONCLUSION: Prolonged WIT impairs long-term graft survival in LDKT. This finding underlines the need to develop strategies to avoid the occurrence of prolonged WIT in LDKT.

In vitro cytokine production of TNFalpha and IL-13 correlates with acute liver transplant rejection.

Individuals may differ in their capacity to produce cytokines. Since cytokines play a key role in allograft rejection, we investigated whether inter-individual differences in cytokine production by in vitro stimulated PBMC are related to the occurrence of acute liver transplant rejection. Our study group comprised 49 liver transplant recipients and 30 healthy individuals. Rejection, which occurred within one month after liver transplantation, was defined in 22 patients ("rejectors") as biopsy-proven rejection, treated with high dose prednisolone. Patients who never experienced rejection episodes were termed as "nonrejectors" (n=27). PBMC of healthy individuals and of liver transplant recipients, collected late after transplantation (mean 3.5 years), were cultured in the presence and absence of Concanavalin A. The production of TNF-alpha, IFN-gamma, IL-10, and IL-13 was measured in supernatant after 1, 2, 3, 4, and 7 days of cell culture. In cell culture, stimulated PBMC of rejectors were found to produce significantly higher levels of TNF-alpha, while there was a trend towards higher production of IFN-gamma and IL-10 as compared to nonrejectors. After grouping patients into high or low cytokine producers based upon reference levels of the healthy individuals using multivariate analysis it was found that occurrence of acute liver transplant rejection correlated to high production of TNF-alpha and low production of IL-13. After stimulated cell culture PBMC of liver transplant recipients show a differential production of TNF-alpha and IL-13 which is correlated with the occurrence of acute liver transplant rejection.