The trans-septal approach in transcatheter mitral valve-in-valve implantation for degenerative bioprosthesis.

BACKGROUND: Transcatheter Mitral Valve-in-Valve Implantation (TMViVI) has recently emerged as a novel therapy for degenerated mitral valve bioprosthesis. Re-operative mitral valve surgery is associated with a substantial risk of mortality and morbidity. The objective of this study was to describe the outcomes of transcatheter mitral valve-in-valve implantations in our cardiac center. METHODS: Twenty-two patients underwent the valve-in-valve procedure because of bioprosthesis degeneration from March 2017 to October 2018. Clinical, echocardiographic, procedural details and survival at follow up were assessed. RESULTS: Eight patients refused re-operative cardiac surgery while others were deemed a high risk for conventional re-operative sternotomy. All patients had TMViVI performed via a trans-septal approach, and the prosthesis was implanted successfully with immediate hemodynamic improvement in 20 patients. One patient had tamponade (4.55%), two had permanent pacemaker insertion (9.09%), two patients had a renal impairment (9.09%), and three patients had vascular complications (13.64%). There was one aborted procedure for the failure to cross the tissue valve with a transcatheter valve, and one patient was converted to an emergency mitral valve surgery. All patients were discharged in NYHA class I/II and NYHA class was markedly improved at one-year follow-up (p = 0.002). CONCLUSIONS: Trans-septal mitral valve-in-valve implantation can be performed safely for degenerative mitral valve bioprosthesis and with favorable early clinical and hemodynamic outcomes.

Prevalence and risk factors of clopidogrel non-response among Saudi patients undergoing coronary angiography.

OBJECTIVES: To estimate the prevalence of clopidogrel non-response and identify its risk factors among Saudi patients.  METHODS: This cross-sectional study was conducted at Prince Sultan Cardiac Center, Riyadh, Kingdom of Saudi Arabia between January and June 2013, to assess the degree of platelet inhibition using the VerifyNow assay (Accumetrics, San Diego, CA, USA) after receiving clopidogrel standard loading dose. Clopidogrel resistance was defined as ≤15% platelet inhibition or greater than 213 P2Y12 reaction units (PRU).  RESULTS: Three hundred and four patients were included in the study. The mean age was 60.3 ± 11.4 years, and 73% were males. Clopidogrel doses were 300 mg (57%), 600 mg (27%), and 75 mg (16%). All patients used aspirin (81 mg in 94%). Approximately 66% (200/304) showed in vitro clopidogrel non-response, 54% had low platelet inhibitions, and 61% had high post-loading PRU. Using multivariate regression analysis that included all significant characteristics; only diabetes (odds ratio [OR]: 2.36, 95% confidence interval [CI]: 1.30-4.27, p=0.005) and higher preloading PRU (OR: 2.39, 95% CI: 1.40-4.11, p=0.002) remained significantly associated with higher clopidogrel non-response while myocardial infarction (OR: 0.34, 95% CI: 0.15-0.81, p=0.014) remained significantly associated with lower clopidogrel non-response. The associations of morbid obesity and diuretics use with higher clopidogrel non-response were slightly attenuated.   CONCLUSION: Our findings indicate a high rate of clopidogrel in-vitro non-response among Saudi patients undergoing coronary angiography.

Efficacy of a single dose intravenous heparin in reducing sheath-thrombus formation during diagnostic angiography: A randomized controlled trial.

BACKGROUND: Femoral arterial sheath thrombosis and distal embolization are well-recognized complications of cardiac catheterization but the occlusion is extremely rare. Heparinized saline flushes are used during diagnostic coronary angiography to prevent thrombus formation within the sheath lumen. However, the use of prophylactic intravenous heparin following the femoral arterial sheath insertion is controversial. The aim of this study is to evaluate the effectiveness of 2000 units of intravenous heparin bolus in comparison to a saline placebo on the thrombus formation within the arterial sheath during the diagnostic coronary angiography. METHODS: Eligible patients were randomized to receive either a study drug or placebo at the time of femoral sheath insertion. The sheath was aspirated and flushed for any presence of thrombus after each catheter exchange and at the end of the procedure. Five milliliters of blood were extracted and visualized on clean gauze followed by a saline flush. The primary end-point was the effectiveness of the study drug on reducing the incidence of sheath-thrombus formation. RESULTS: Three hundred and twenty patients were randomized into two arms. Three hundred and four patients were analyzed: 147 patients in heparin arm and 157 patients in placebo arm after exclusion of 13 patients in heparin arm and three in placebo arm because of incomplete reports. The baseline characteristics were similar and sheath-thrombi formation was observed in 20% of the total cohort. Of the heparin arm, 12% (19 patients) developed sheath-thrombus formation, whereas 26% (42 patients) in the placebo arm, p-value = 0.002. An adjusted logistic regression model showed that the only predictor for the sheath-thrombus formation was the study drug (i.e. heparin). The odds ratio of developing a thrombus in the control arm was 2.5 (95% CI: 1.4-4.5, p = 0.003). There were no bleeding events observed. CONCLUSION: The risk of thrombus formation is significant and intravenous heparin significantly reduced thrombus formation during diagnostic coronary angiography, with no excess bleeding events.

Do We Need Premedication Before Coronary Angiography? A Controlled Clinical Trial.

BACKGROUND: Premedication with benzodiazepines has been thought to reduce patient anxiety, pain perception, and non-catheter-induced coronary spasms and may increase procedure-related complications. We used to routinely provide premedication with diazepam and chlorpheniramine before cardiac catheterization procedures. However the benefits of such a treatment are not well established here. Therefore, we designed this study to test whether the routine use of premedication during coronary angiography is needed. METHODS: A total of 200 consecutive patients scheduled to undergo either diagnostic or therapeutic coronary angiographic procedures were randomized to receive either premedication with diazepam (5 mg) and chlorpheniramine (4 mg) 60 minutes prior to their procedures (n = 100) or no premedication (n = 100). The administration of intravenous midazolam during the procedures was permitted at the operator's discretion. The primary endpoints were anxiety and pain perception during the procedure. RESULTS: A total of 200 patients with similar baseline characteristics were randomized into two groups. The first group received oral premedication with diazepam (5 mg) and chlorphenamine (4 mg) 60 minutes prior to their procedures, and the other group did not receive premedication. We observed no differences in periprocedural pain perception (31% in the premedicated group versus 29% in the non-premedicated group; P = 0.75) or anxiety (59% in the premedicated group versus 50% in the non-premedicated group; P = 0.2). Interestingly, local pain was more pronounced in the premedicated patients than in the non-premedicated patients (30% versus 16%, respectively; P = 0.018). There were no contrast-related reactions reported in either group. CONCLUSION: Treatment with oral diazepam and chlorphenamine prior to cardiac catheterization and percutaneous coronary intervention does not alter rates of anxiety, periprocedural pain.

Very delayed coronary stent fracture: A case report.

A stent fracture is an emerging complication of the coronary stents. There are numerous risk factors for stent fractures; which include forceful exaggerated motion in the atrioventricular groove seen in right coronary artery, long stent, an ostial lesion at the point of maximum curvature in a tortuous vessel, stent over-expansion, stent overlapping with different size stents, complex lesion after stenting of a totally occluded vessel, Cypher stent and a highly mobile segment causing high mechanical stress. Furthermore, chronic stretch at specific vessel sites as bends may lead to late occurrence of fracture. Here we report a case of 40-year-old male who had two overlapping Cypher stents (3.0 × 13 mm and 2.75 × 18 mm) deployed at mid left anterior descending artery 2 years earlier presented with progressive chest pain.

Lessons from the SYNTAX trial.

Despite the fact that CABG is the standard of care for patients with multivessel coronary arteries and/or left main stem stenosis, PCI has become a rival to CABG in patients with multivessel coronary artery disease or left main disease. However, the need for repeat revascularization, in-stent stenosis and thrombosis remain the achilis heal of PCI. SYNTAX trial randomized patients with left main disease and/or three-vessel disease to PCI with TAXus stent or CABG with the concept that PCI is not inferior to CABG. At 1 and 2 years follow up, MACCE was significantly increased in PCI patients mainly attributed to increased rate of repeat revascularization; however, stroke was significantly more with CABG. The composite safety endpoint of death/stroke/MI was comparable between the 2 groups. Therefore the criterion for non-inferiority was not met. What we learn from SYNTAX is that multi disciplinary team approach should be the standard of care when recommending treatment in more complex coronary artery disease. SYNTAX makes interventionists and surgeons come together, it may set the benchmark for MVD revascularization. PCI and CABG should be considered complementary rather than competitive revascularization strategies. There is no substitute for sound clinical judgment that takes into account the patient's overall clinical profile, functionality, co-morbidities, as well as the patient's coronary anatomy. The SYNTAX Score should be utilized to decide on treatment of patients with LM/MVD. Patients with low and intermediate score can be treated with PCI or CABG with equal results. Those with high score do better with CABG. SYNTAX trial showed that 66% of patients with 3VD or LMD are still best treated with CABG. In the remaining 1/3 of patients with low syntax score, PCI may be considered as an alternative to surgery. Finally, medical treatment should be optimized in patients going for CABG.