Clinical impact of complex percutaneous coronary intervention in the pre-TAVR workup.

INTRODUCTION AND OBJECTIVES: In patients undergoing percutaneous coronary intervention (PCI) in the workup pre-transcatheter aortic valve replacement (TAVR), the clinical impact of coronary revascularization complexity remains unknown. This study sought to examine the impact of PCI complexity on clinical outcomes after TAVR in patients undergoing PCI in the preprocedural workup. METHODS: This was a multicenter study including consecutive patients scheduled for TAVR with concomitant significant coronary artery disease. Complex PCI was defined as having at least 1 of the following features: 3 vessels treated, ≥ 3 stents implanted, ≥ 3 lesions treated, bifurcation with 2 stents implanted, total stent length >60mm, or chronic total occlusion. The rates of major adverse cardiac events (MACE), including cardiovascular mortality, myocardial infarction, and coronary revascularization were evaluated. RESULTS: A total of 1550 patients were included, of which 454 (29.3%) underwent complex PCI in the pre-TAVR workup. After a median follow-up period of 2 [1-3] years after TAVR, the incidence of MACE was 9.6 events per 100 patients-years. Complex PCI significantly increased the risk of cardiac death (HR, 1.44; 95%CI, 1.01-2.07), nonperiprocedural myocardial infarction (HR, 1.52; 95%CI, 1.04-2.21), and coronary revascularization (HR, 2.46; 95%CI, 1.44-4.20). In addition, PCI complexity was identified as an independent predictor of MACE after TAVR (HR, 1.31; 95%CI, 1.01-1.71; P=.042). CONCLUSIONS: In TAVR candidates with significant coronary artery disease requiring percutaneous treatment, complex revascularization was associated with a higher risk of MACE. The degree of procedural complexity should be considered a strong determinant of prognosis in the PCI-TAVR population.

Incidence, Predictors, and Prognostic Impact of Bleeding Events After TAVR According to VARC-3 Criteria.

BACKGROUND: The updated Valve Academic Research Consortium (VARC) definition for bleeding events after transcatheter aortic valve replacement (TAVR) lacks of clinical validation. OBJECTIVES: The aim of this study was to determine the incidence, predictors, and clinical impact of bleeding events following TAVR as defined by recent VARC-3 criteria. METHODS: A total of 2,384 consecutive patients with severe symptomatic aortic stenosis undergoing TAVR were included. Early (at index hospitalization) and late (after hospital discharge) bleeding complications were defined according to VARC-3 criteria as type 1, 2, 3, or 4. Baseline, procedural, and follow-up (24 [IQR: 12-43] months) data were prospectively collected. RESULTS: Bleeding events occurred in 761 patients (31.9%): types 1, 2, 3, and 4 in 169 (22.2%), 399 (52.4%), 149 (19.6%), and 44 (5.8%) patients, respectively. The primary vascular access site and gastrointestinal locations were the most common bleeding sources among early and late bleeding events, respectively. Female sex, thoracotomy access, larger (14-F) sheath use, and dual antiplatelet therapy determined an increased risk of early bleeding events (P < 0.02 for all). The use of the radial artery for secondary access was associated with a significant risk reduction of early bleeding (P < 0.001). Type 2 and type 3 events were associated with an increased mortality risk at 30-day (HR: 2.94 [95% CI: 1.43-6.03; P = 0.003] and HR: 4.91 [95% CI: 2.19-11.03; P < 0.001], respectively) and 1-year (HR: 1.86 [95% CI: 1.28-2.69; P = 0.001] and HR: 2.28 [95% CI: 1.41-3.66; P = 0.001], respectively) follow-up. A similar prognostic pattern was observed when applying VARC-2 criteria but with a much lower global incidence of early bleeding events (19% vs 27%; P < 0.001). CONCLUSIONS: Bleeding events after TAVR were associated with poorer short- and long-term survival. The magnitude of this correlation was proportional to bleeding severity defined according to VARC-3 criteria. Further studies on bleeding prevention following TAVR are warranted to improve procedural safety and patient prognosis.

Late Bleeding Events in Patients Undergoing Percutaneous Coronary Intervention in the Workup Pre-TAVR.

BACKGROUND: In patients undergoing percutaneous coronary intervention (PCI) in the work-up pre-transcatheter aortic valve replacement (TAVR), the incidence and clinical impact of late bleeding events (LBEs) remain largely unknown. OBJECTIVES: This study sought to determine the incidence, clinical characteristics, associated factors, and outcomes of LBEs in patients undergoing PCI in the work-up pre-TAVR. METHODS: This was a multicenter study including 1,457 consecutive patients (mean age 81 ± 7 years; 41.5% women) who underwent TAVR and survived beyond 30 days. LBEs (>30 days post-TAVR) were defined according to the Valve Academic Research Consortium-2 criteria. RESULTS: LBEs occurred in 116 (7.9%) patients after a median follow-up of 23 (IQR: 12-40) months. Late bleeding was minor, major, and life-threatening or disabling in 21 (18.1%), 63 (54.3%), and 32 (27.6%) patients, respectively. Periprocedural (<30 days post-TAVR) major bleeding and the combination of antiplatelet and anticoagulation therapy at discharge were independent factors associated with LBEs (P ≤ 0.02 for all). LBEs conveyed an increased mortality risk at 4-year follow-up compared with no bleeding (43.9% vs 36.0; P = 0.034). Also, LBE was identified as an independent predictor of all-cause mortality after TAVR (HR: 1.39; 95% CI: 1.05-1.83; P = 0.020). CONCLUSIONS: In TAVR candidates with concomitant significant coronary artery disease requiring percutaneous treatment, LBEs after TAVR were frequent and associated with increased mortality. Combining antiplatelet and anticoagulation regimens and the occurrence of periprocedural bleeding determined an increased risk of LBEs. Preventive strategies should be pursued for preventing late bleeding after TAVR, and further studies are needed to provide more solid evidence on the most safe and effective antithrombotic regimen post-TAVR in this challenging group of patients.

The Effect of Trimethoprim on Thiamine Absorption: A Transporter-Mediated Drug-Nutrient Interaction.

Trimethoprim is predicted to inhibit several thiamine transporters, including the primary thiamine intestinal absorptive transporter, ThTR-2, and the hepatic and renal organic cation transporters, OCT1, OCT2, and MATEs. To investigate the effect of trimethoprim on thiamine absorption, studies were conducted in cells, mice, and healthy volunteers and supported by use of real-world data. In a randomized, crossover clinical study, seven healthy volunteers were given a single oral dose of thiamine or thiamine plus trimethoprim, followed by blood sampling. The thiamine area under the curve (AUC) increased with trimethoprim co-administration (P value = 0.031). Similar results were seen in mice. Trimethoprim appeared to act on thiamine absorption through inhibition of hepatic OCT1 as evidenced from its ability to modulate levels of isobutyrylcarnitine and propionylcarnitine, OCT1 biomarkers identified from metabolomic analyses. Real-world data further supported this finding, showing an association between trimethoprim use and higher levels of triglycerides, LDL cholesterol, and total cholesterol, consistent with OCT1 inhibition (P values: 2.2 × 10-16 , 5.75 × 10-7 , and 5.82 × 10-7 , respectively). These findings suggest that trimethoprim increases plasma levels of thiamine by inhibiting hepatic OCT1. Trimethoprim reduced urinary excretion and clearance of biomarkers for OCT2 and MATEs, consistent with inhibition of renal organic cation transporters. This inhibition did not appear to play a role in the observed increases in thiamine levels. This study highlights the potential for drug-nutrient interactions involving transporters, in addition to transporters' established role in drug-drug interactions.

Myocardial Injury After Transcatheter Aortic Valve Replacement According to VARC-3 Criteria.

BACKGROUND: The Valve Academic Research Consortium (VARC)-3 definition for myocardial injury after transcatheter aortic valve replacement (TAVR) lacks of clinical validation. OBJECTIVES: This study sought to determine the incidence, predictors, and clinical impact of periprocedural myocardial injury (PPMI) following TAVR as defined by recent VARC-3 criteria. METHODS: We included 1,394 consecutive patients who underwent TAVR with a new-generation transcatheter heart valve. High-sensitivity troponin levels were assessed at baseline and within 24 hours after the procedure. PPMI was defined according to VARC-3 criteria as an increase ≥70 times in troponin levels (vs ≥15 times according to the VARC-2 definition). Baseline, procedural, and follow-up data were prospectively collected. RESULTS: PPMI was diagnosed in 193 (14.0%) patients. Female sex and peripheral artery disease were independent predictors of PPMI (P < 0.01 for both). PPMI was associated with a higher risk of mortality at 30-day (HR: 2.69, 95% CI: 1.50-4.82; P = 0.001) and 1-year (for all-cause mortality, HR: 1.54; 95% CI: 1.04-2.27; P = 0.032; for cardiovascular mortality, HR: 3.04; 95% CI: 1.68-5.50; P < 0.001) follow-up. PPMI according to VARC-2 criteria had no impact on mortality. CONCLUSIONS: About 1 out of 10 patients undergoing TAVR in the contemporary era had PPMI as defined by recent VARC-3 criteria, and baseline factors like female sex and peripheral artery disease determined an increased risk. PPMI had a negative impact on early and late survival. Further studies on the prevention of PPMI post-TAVR and implementing measures to improve outcomes in PPMI patients are warranted.

Antithrombotic Management After Left Atrial Appendage Closure: Current Evidence and Future Perspectives.

Left atrial appendage closure is an alternative to chronic oral anticoagulation to prevent embolic events related to nonvalvular atrial fibrillation. After device implantation, antithrombotic treatment is prescribed to prevent device-related thrombosis, a dreadful complication associated with an increased risk of ischemic events. However, the optimal antithrombotic treatment after left atrial appendage closure, effective on both device-related thrombus prevention and bleeding risk mitigation, remains to be determined. In more than 10 years experience with left atrial appendage closure, a wide range of antithrombotic treatments have been used, mostly in observational studies. In this review, we analyzed the body of evidence for each antithrombotic regimen after left atrial appendage closure to provide tools to guide the physician choice and describe future perspectives in the field.

A silica-based antioxidant nanoparticle for oral delivery of Camptothecin which reduces intestinal side effects while improving drug efficacy for colon cancer treatment.

Camptothecin (CPT) is a potent anticancer agent for the treatment of colorectal cancer; however, it exhibits some limitations, including poor solubility, low stability, and low bioavailability via oral administration, which restrict its usability in clinical treatments. In addition, overproduction of reactive oxygen species (ROS) during chemotherapy induces drug resistance and severe intestinal side effects. In this study, silica-installed ROS scavenging nanoparticles (siRNP) with 50-60 nm in diameter were employed to overcome the aforementioned drawbacks of CPT. The solubility of CPT was significantly improved by incorporating it into the core of the nanoparticle, forming CPT-loaded siRNP (CPT@siRNP). The anticancer activity of CPT@siRNP against colorectal cancer cells (C-26) in vitro was significantly improved as compared to free CPT through higher efficiency of intracellular internalization and induction of apoptosis. Owing to its antioxidant properties, CPT@siRNP reduced cytotoxicity to normal endothelial cells, which was in sharp contrast to the high toxicity of free CPT. Oral administration of CPT and CPT@siRNP to the C-26 tumor-bearing mice exhibited antitumor activity, accompanied by effective suppression of tumor growth. Although CPT treatment suppressed tumor progression, it caused severe side effects, including intestinal damage and significant bodyweight loss. Interestingly, such noticeable side effects were not observed in the mice treated with CPT@siRNP, and the effect of tumor growth inhibition tended to be similar to or higher than that of CPT treatment. The results obtained in this study indicate that CPT@siRNP is a potential therapeutic nanomedicine for the treatment of colon cancer. STATEMENT OF SIGNIFICANCE: Here we employed silica-containing antioxidant nanoparticle (siRNP) as promising oral delivery nanocarrier of campothecin (CPT) to treat colon cancer. The design of siRNP via covalent conjugation of antioxidant nitroxide radicals and the silanol groups in the polymer backbone contributes to a significant increase in the absorption of hydrophobic drug molecules inside the core and enhances the stability of nanoparticles in the gastrointestinal environment for oral drug delivery. CPT-loaded siRNP (CPT@siRNP) significantly improved solubility of CPT. As compared to free CTP, the CPT@siRNP treatment showed a significantly higher toxicity to colon cancer cell, inhibition of cancer cell migration, and induction of apopotosis. With the antioxidant feature, siRNP also significantly suppressed the intestinal side effects caused by CPT treatment in tumor-bearing mouse model.

Unincorporated iron pool is linked to oxidative stress and iron levels in Caenorhabditis elegans.

Free radicals or reactive oxygen species (ROS) are relatively short-lived and are difficult to measure directly; so indirect methods have been explored for measuring these transient species. One technique that has been developed using Escherichia coli and Saccharomyces cerevisiae systems, relies on a connection between elevated superoxide levels and the build-up of a high-spin form of iron (Fe(III)) that is detectable by electron paramagnetic resonance (EPR) spectroscopy at g = 4.3. This form of iron is referred to as "free" iron. EPR signals at g = 4.3 are commonly encountered in biological samples owing to mononuclear high-spin (S = 5/2) Fe(III) ions in sites of low symmetry. Unincorporated iron in this study refers to this high-spin Fe(III) that is captured by desferrioxamine which is detected by EPR at g value of 4.3. Previously, we published an adaptation of Fe(III) EPR methodology that was developed for Caenorhabditis elegans, a multi-cellular organism. In the current study, we have systematically characterized various factors that modulate this unincorporated iron pool. Our results demonstrate that the unincorporated iron as monitored by Fe(III) EPR at g = 4.3 increased under conditions that were known to elevate steady-state ROS levels in vivo, including: paraquat treatment, hydrogen peroxide exposure, heat shock treatment, or exposure to higher growth temperature. Besides the exogenous inducers of oxidative stress, physiological aging, which is associated with elevated ROS and ROS-mediated macromolecular damage, also caused a build-up of this iron. In addition, increased iron availability increased the unincorporated iron pool as well as generalized oxidative stress. Overall, unincorporated iron increased under conditions of oxidative stress with no change in total iron levels. However, when total iron levels increased in vivo, an increase in both the pool of unincorporated iron and oxidative stress was observed suggesting that the status of the unincorporated iron pool is linked to oxidative stress and iron levels.

A matched case control study with propensity score balancing examining the protective effect of paracetamol against parentally reported apnoea in infants.

BACKGROUND: Central apnoea occurs in infants and if not detected leads to death. Central apnoea is a prostaglandin E(2) (PGE2) mediated effect that is susceptible to pharmacologic manipulation in animal models. Paracetamol and ibuprofen are centrally and peripherally acting PGE2 inhibitors, respectively. AIM: To determine if infants who had received paracetamol or ibuprofen are relatively protected from apnoea. METHODS: We performed a matched case control study using propensity score balancing to adjust for non-random drug assignment. We included infants from prospective studies of central apnoea and bronchiolitis. We matched on age, prematurity and fever to adjust for the infants' underlying risk of apnoea. The primary outcome measure was odds of exposure to paracetamol or ibuprofen by apneic infants compared to their controls. RESULTS: Forty-two apneic and 729 non-apneic infants were identified. Infants with apnoea were younger than those without, median age 6.5 versus 12.2 weeks and were more likely to be premature. These differences were balanced using matching. Differences between those who did and did not receive paracetamol were satisfactorily balanced using the propensity score. Ibuprofen was used too infrequently to analyse it further. In the unadjusted analysis fewer apneic infants had had prior paracetamol use 5/42 (12%) versus 211/729 (29%) or prior ibuprofen use 1/42 (2%) versus 51/729 (7%). In the adjusted analysis paracetamol was protective against apnoea; OR 0.30 (95% CI 0.11, 0.78). CONCLUSIONS: Prior paracetamol use was protective against apnoea in infants. We could not demonstrate an effect for ibuprofen.

Nebivolol: a selective beta(1)-adrenergic receptor antagonist that relaxes vascular smooth muscle by nitric oxide- and cyclic GMP-dependent mechanisms.

Nebivolol is a highly selective beta(1)-adrenergic receptor antagonist that also possesses vasodilator properties that are attributed largely to nitric oxide (NO). The objective of the present study was to elucidate in more detail the mechanisms by which nebivolol relaxes vascular smooth muscle. In the canine species, nebivolol caused relaxation of isolated precontracted rings of coronary artery and pulmonary artery largely by endothelium-dependent, NO-dependent, and cyclic GMP-dependent mechanisms. Vasorelaxation was inhibited by N(G)-methylarginine, and this inhibition was reversed by addition of excess L-arginine. Moreover, the vasorelaxant responses to nebivolol were markedly inhibited by oxyhemoglobin, methylene blue, and 1H-[1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one (ODQ), whereas vasorelaxation was enhanced by zaprinast. Rat aortic ring preparations, however, relaxed in response to nebivolol by both endothelium-dependent and endothelium-independent mechanisms, both involving NO, and cyclic GMP. Endothelium-dependent and endothelium-independent vasorelaxation were inhibited by oxyhemoglobin, methylene blue, and ODQ. However, only endothelium-dependent vasorelaxation in response to nebivolol was inhibited by N(G)-methylarginine. Additional experiments ruled out other endothelium-independent vasorelaxant mechanisms. In conclusion, the vasodilator responses to nebivolol involve NO and cyclic GMP in both vascular endothelial and smooth muscle cells.

Nebivolol inhibits vascular smooth muscle cell proliferation by mechanisms involving nitric oxide but not cyclic GMP.

The objective of this study was to elucidate the mechanisms by which nebivolol, a cardio-selective beta-adrenergic receptor antagonist, inhibits rat aortic smooth muscle cell (RASMC) proliferation. Nebivolol was compared with DETA-NO and S-nitroso-N-acetylpenicillamine (SNAP), two nitric oxide (NO) donor agents, and alpha-difluoromethylornithine (DFMO), a known inhibitor of ornithine decarboxylase (ODC). All four test agents inhibited RASMC proliferation in a concentration-dependent manner, with nebivolol being the most potent (IC(50) = 4.5 microM), whereas atenolol, another relatively selective beta(1)-blocker, was inactive. DFMO, nebivolol, and DETA-NO interfered with cell proliferation in a cell-density-dependent manner, the lower the cell density the greater the inhibition of cell proliferation. The cytostatic effects of nebivolol and DETA-NO were completely independent of cyclic GMP, as neither ODQ (cytosolic guanylyl cyclase inhibitor) nor zaprinast (cyclic GMP phosphodiesterase inhibitor) affected the antiproliferative action of nebivolol or DETA-NO. The cytostatic effects of nebivolol, SNAP, and DFMO were largely prevented by the addition of excess putrescine, but not ornithine, to cell cultures. Moreover, nebivolol caused a marked reduction in the intracellular levels of putrescine, spermidine, and spermine. Like DFMO, nebivolol and DETA-NO interfered with the G(1)-phase to S-phase cell cycle transition in RASMC. These observations confirm previous findings that DFMO and NO interfere with RASMC proliferation by inhibiting ODC and polyamine production and provide evidence that nebivolol works by the same mechanism.