Updates 30th January 2017
Early Detection of Medical Device Safety Issues through Prospective Registry Surveillance
As the use of implantable medical devices increases, so does the need for early and continuous follow-up and evaluation of safety and efficacy in clinical use. Recently the CSANZ and ACOR have worked with the Commonwealth Department of Health on the development and implementation of a national register for surveillance of adverse events for cardiac devices.
In the New England Journal of Medicine on January 25th 2017, Resnic et al describe the utility of such prospective registry surveillance for early detection of adverse events associated with a vascular device.
The device surveillance included prospective registry collection and advanced active surveillance algorithms for comparison of outcomes between devices in over 70,000 patients. These protocols allowed early detection of device-related complications.
The authors concluded that “A strategy of prospective, active surveillance of a clinical registry rapidly identified potential safety signals among recipients of an implantable vascular-closure device, with initial alerts occurring within the first 12 months of monitoring”.
The findings of this study support current CSANZ/ACOR efforts and provide useful information about new and efficient data monitoring and analysis protocols.
Feasibility of Transcatheter Mitral Valve Replacement for Symptomatic Mitral Regurgitation
Although catheter-based aortic valve replacement (TAVR) has been available for some years, catheter based mitral valve replacement (TMVR) has posed considerably greater technical challenges.
In the recent issue of the Journal of the American College of Cardiology, Muller an coworkers describe the outcomes of a feasibility study of TMVR. This prospective
study examined the feasibility of TMVR using a self-expanding prosthesis in symptomatic patients with native MR who were at high risk for cardiac surgery.
Thirty patients (age 75.6 ± 9.2 years; 25 men) with grade 3 or 4 MR underwent TMVR. The MR etiology was secondary (n = 23), primary (n = 3), or mixed pathology (n = 4). The Society of Thoracic Surgeons Predicted Risk of Mortality was 7.3 ± 5.7%. Successful device implantation was achieved in 28 patients (93.3%). At 30 days, TTE showed mild (1+) central MR in 1 patient, and no residual MR in the remaining 26 patients with valves in situ. The left ventricular end-diastolic volume index decreased (90.1 ± 28.2 ml/m2 at baseline vs. 72.1 ± 19.3 ml/m2 at follow-up; p = 0.0012), as did the left ventricular end-systolic volume index (48.4 ± 19.7 ml/m2 vs. 43.1 ± 16.2 ml/m2; p = 0.18). Seventy-five percent of the patients reported mild or no symptoms at follow-up (New York Heart Association functional class I or II). Successful device implantation free of cardiovascular mortality, stroke, and device malfunction at 30 days was 86.6%.
Deployment of the device encountered problems in 3 patients, in whom the device was retrieved acutely through the delivery sheath. A fourth patient had malpositioning of the device with mild paravalvar regurgitation. One patient died of pneumonia and 19 were discharged home with the remainder being discharged to rehabilitation. Duration of hospital stay was 5 to 35 days.
Tthe authors concluded that “TMVR is an effective and safe therapy for selected patients with symptomatic native MR. Further evaluation of TMVR using prostheses specifically designed for the mitral valve is warranted. “
Tracheal Intubation is Not Associated with Improved Survival of In-Hospital Cardiac Arrest
Endotracheal intubation is common during adult in-hospital cardiac arrest, but little is known about the association between tracheal intubation and survival in this setting. In the January 24 2017 issue of JAMA, Andersen et al report the findings of a large-scale observational cohort study conducted over 15 years.
The propensity-matched cohort was selected from 108 079 adult patients at 668 hospitals. The median age was 69 years (interquartile range, 58-79 years), 45,073 patients (42%) were female, and 24,256 patients (22.4%) survived to hospital discharge. Of 71,615 patients (66.3%) who were intubated within the first 15
minutes, 43,314 (60.5%) were matched to a patient not intubated in the same minute. Survival was lower among patients who were intubated compared with those not intubated: 7,052 of 43,314 (16.3%) vs 8,407 of 43,314 (19.4%), respectively (risk ratio [RR] = 0.84; 95% CI, 0.81-0.87; P < .001).
The proportion of patients with return of spontaneous circulation was lower among intubated patients than those not intubated: 25,022 of 43,311 (57.8%) vs 25,685 of 43,310 (59.3%), respectively (RR = 0.97; 95% CI, 0.96-0.99; P < .001). Good functional outcome was also lower among intubated patients than those not intubated: 4,439 of 41,868 (10.6%) vs 5,672 of 41,733 (13.6%), respectively (RR = 0.78; 95% CI, 0.75-0.81; P < .001). Although differences existed in prespecified subgroup analyses, intubation was not associated with improved outcomes in any subgroup.
The authors conclude that “among adult patients with in-hospital cardiac arrest, initiation of tracheal intubation within any given minute during the first 15 minutes of resuscitation, compared with no intubation during that minute, was associated with decreased survival to hospital discharge. These findings do not support early tracheal intubation for adult in-hospital cardiac arrest.”