Oral anticoagulant management of patients with mechanical heart valves at the Salam Centre of Khartoum: Observations on quality of anticoagulation and thrombotic risk.

INTRODUCTION: Rheumatic heart disease with mechanical heart valve (MHV) replacement is common in Africa. However, MHV requires long-life anticoagulation and managing this can be challenging. METHODS AND RESULTS: We report data of a prospective observational study conducted between August 2018 and September 2019 in MHV patients in the Salam Centre for Cardiac Surgery built in Khartoum, by Emergency, an Italian Non-Governmental Organization, to evaluate the quality of anticoagulation control and the risk of thrombotic complications. RESULTS: We studied 3647 patients (median age 25.1 years; 53.9 % female). Median Time in Therapeutic Range (TTR) was 53 % (interquartile range 37 % to 67 %) and 70 thrombotic events (rate 1.8 × 100 pt-years [95 % CI 1.38-2.23]) were recorded. Among patients in the first quartile of TTR (≤37 %), we recorded 34/70 (48.6 %) of all thrombotic events (rate 3.7 × 100 pt-years [95 % CI 2.5-5.1]), with a high mortality rate (2.2 × 100 pt-years [95 % CI 1.3-3.3]). In patients with guideline-recommended TTR (≥65 %) the event rate was 0.8 × 100 pt-years for thrombotic events [95 % CI 0.3-1.5] and 0.4 × 100 pt-years for mortality [95 % CI 0.1-0.9]. Multivariable analysis showed that having a TTR in the lowest quartile (≤37 %) and being noncompliant are significantly associated with increased thrombotic risk. Aspirin use or different valve type did not influence the thrombotic risk. Almost 40 % of all thromboembolic complications could have been potentially prevented by further improving VKA management to obtain a TTR > 37 %. CONCLUSION: The thrombotic risk of MHV patients on VKAs living in a low-income country like Sudan is associated with low quality of anticoagulation control. Efforts should be made to decrease the number of non-compliant patients and to reach a guideline-recommended TTR of ≥65 %.

Risk of syncope during work.

AIMS: Little is known regarding the overall prevalence of syncope in a population of workers and the risk of occurrence during working time. METHODS AND RESULTS: A total of 452 consecutive workers (mean age: 46 ± 9 years) were invited to answer an anonymous questionnaire. They had been employed for 22 ± 10 years for a total of 9765 years worked. In the cohort, 160 subjects (35%) reported a total of 465 episodes of syncope during their lives; 64 (14%) suffered a syncopal episode after the start of employment, but only 26 (5.7%) reported syncope at work, 7 (1.5%) having had 2 episodes, and 1 (0.2%) 3 episodes (total: 36 episodes). The risk of syncope during work was 4.6 times higher for those who had a prior history of syncope [18 of 138 (13%)] than for those who did not [8 of 314 (3%), P = 0.001]. The occurrence of syncope during work for the patients with a history of syncope was one syncopal episode in every 99 years worked and for those who had already had an episode during work, one episode in every 16 years worked. Only one patient experienced minor trauma as a consequence of syncope during work and three were referred to the emergency department. All patients continued their employment without any problems. CONCLUSION: The prevalence of syncope during work is low and its impact is benign. The probability of syncope during work is higher for subjects with a history of syncope.

An observational registry on efficacy and safety of the right ventricular outflow tract as a site for ICD leads: results of the EFFORT (EFFicacy Of Right ventricular outflow Tract as site for ICD leads) registry.

BACKGROUND: Although pacing from the right ventricular outflow tract (RVOT) has been shown to be safe and feasible in terms of sensing and pacing thresholds, its use as a site for implantable cardioverter defibrillator (ICD) leads is not common. This is probably due to physicians' concerns about defibrillation efficacy. To date, only one randomized trial, involving 87 enrolled patients, has evaluated this issue. OBJECTIVE: The aim of this observational study has been to compare safety (primary combined end point: efficacy of a 14-J shock in restoring sinus rhythm, R wave amplitude >4 mV and pacing threshold <1 V at 0.5 ms) and efficacy (in terms of effectiveness of a 14-J shock in restoring sinus rhythm after induction of VF, secondary end point) of two different sites for ICD lead positioning: RVOT and right ventricular apex (RVA). METHODS: The study involved 185 patients (153 males; aged 67 ± 10 years; range, 28-82 years). Site of implant was left to physician's decision. After implant, VF was induced with a 1-J shock over the T wave or--if this method was ineffective--with a 50-Hz burst, and a 14-J shock was tested in order to restore sinus rhythm. If this energy was ineffective, a second shock at 21 J was administered and--eventually--a 31-J shock followed--in case of inefficacy--by a 360-J biphasic external DC shock. Sensing and pacing thresholds were recorded in the database at implant, together with acute (within 3 days of implant) dislodgement rate. RESULTS: The combined primary end point was reached in 57 patients in the RVOT group (0.70%) and in 81 patients in the RVA group (0.79%). The 14-J shock was effective in 159 patients, 63 in the RVOT group (77%) and 86 in the RVA group (83%). Both the primary and the secondary end points are not statistically different. R wave amplitude was significantly lower in the RVOT group (10.9 ± 5.2 mV vs. 15.6 ± 6.4 mV, p < 0.0001), and pacing threshold at 0.5 ms was significantly higher (0.64 ± 0.25 V vs. 0.52 ± 0.20 V, p < 0.01), but these differences do not seem to have a clinical meaning, given that the lower values are well above the accepted limits in clinical practice. CONCLUSIONS: Efficacy and safety of ICD lead positioning in RVOT is comparable to RVA. Even if we observed statistically significant differences in sensing and pacing threshold, the clinical meaning of these differences is--in our opinion--irrelevant.