Impact of preprocedural mitral regurgitation upon mortality after transcatheter aortic valve implantation (TAVI) for severe aortic stenosis.

OBJECTIVE: To identify the effects of preprocedural significant mitral regurgitation (MR) and change in MR severity upon mortality after transcatheter aortic valve implantation (TAVI) using the Edwards SAPIEN system. METHODS: A retrospective analysis of 316 consecutive patients undergoing TAVI for aortic stenosis at a single centre in the UK between March 2008 and January 2013. Patients were stratified into two groups according to severity of MR: ≥grade 3 were classed as significant and ≤grade 2 were non-significant. Change in MR severity was assessed by comparison of baseline and 30-day echocardiograms. RESULTS: 60 patients had significant MR prior to TAVI (19.0%). These patients were of higher perioperative risk (logistic EuroScore 28.7±16.6% vs 20.3±10.7%, p=0.004) and were more dyspnoeic (New York Heart Association class IV 20.0% vs 7.4%, p=0.014). Patients with significant preprocedural MR displayed greater 12-month and cumulative mortality (28.3% vs 20.2%, log-rank p=0.024). Significant MR was independently associated with mortality (HR 4.94 (95% CI 2.07 to 11.8), p<0.001). Of the 60 patients with significant MR only 47.1% had grade 3-4 MR at 30 days (p<0.001). Patients in whom MR improved had lower mortality than those in whom it deteriorated (log-rank p=0.05). CONCLUSIONS: Significant MR is frequently seen in patients undergoing TAVI and is independently associated with increased all-cause mortality. Yet almost half also exhibit significant improvements in MR severity. Those who improve have better outcomes, and future work could focus upon identifying factors independently associated with such an improvement.

Spontaneous coronary artery dissection.

We present a case of a 43-year-old lady who presented with an acute coronary syndrome, but without any cardiac risk factors or previous cardiac symptoms, and who had a spontaneous coronary artery dissection. This was successfully treated with percutaneous coronary intervention. A brief discussion of this clinical entity and literature review is presented.

Intracardiac echocardiography.

Intracardiac echocardiography (ICE) is increasingly being used to guide percutaneous interventional procedures, principally the closure of interatrial septal abnormalities, and to support electrophysiological procedures. Clear views of intracardiac structures can help a number of other procedures, such as myocardial biopsy and paravalvular leak closure. The main advantages of ICE over transoesophageal echocardiography during closure of atrial septal defects are that the use of ICE eliminates the need for a general anaesthetic, affords clearer imaging, shorter procedure times and reduces hospital stays and radiation doses. The principal disadvantage is the additional cost of the catheter, though this can be offset by improved turnaround times and reduced personnel costs.

Contrasting liver function test patterns in obstructive jaundice due to biliary strictures [corrected] and stones.

BACKGROUND: Obstructive jaundice is believed to be characterized by abnormalities of alkaline phosphatase (ALP), rather than aspartate transaminase (AST). AIM: To compare liver function tests (LFTs) in obstructive jaundice due to malignant strictures with those of jaundice due to gallstones. METHODS: LFTs were measured immediately before endoscopic retrograde cholangio-pancreatography (ERCP) in 207 jaundiced patients. Group 1 (n = 69) had malignant strictures, group 2 (n = 97) had common bile duct stone(s), and group 3 (n = 41) appeared to have recently passed a stone. LFTs in groups 2 and 3 were also analysed at maximal liver enzyme derangement, maximum hyperbilirubinaemia and during acute pain episodes. RESULTS: Group 1 had higher median bilirubin, AST and ALP levels than groups 2 or 3 (p < 0.001). In group 1, median rise in ALP exceeded that in AST (4.3 x normal upper limit (NUL) vs. 2.6 x NUL, p < 0.01), but in groups 2 and 3, AST and ALP were similarly elevated (both approximately 2 x NUL). At the time of maximum enzyme derangement in groups 2 and 3, median AST elevation (4.4 x NUL, 185 IU/l) exceeded that for ALP (2.4 x NUL, 276 U/l), (p < 0.001), and this was also true at peak hyperbilirubinaemia in these groups (AST 3.6 x NUL, ALP 2.4 x NUL, p < 0.01. Similarly, severe pain episodes in groups 2 and 3 were accompanied by greater elevations in bilirubin and AST, but not ALP, compared with levels at ERCP. DISCUSSION: The conventional wisdom that ALP rises more than AST in obstructive jaundice holds true where the jaundice is due to strictures, but in obstructive stone disease, the rise in AST may equal that in ALP, or even exceed it during maximum jaundice and during painful episodes. Clinicians should consider the possibility of extrahepatic biliary obstruction, even when AST is the predominantly elevated enzyme.

Accuracy, information, and response time in a saccadic decision task.

Reaction times generally follow a simple law economically described by the LATER model, in which a decision signal rises linearly in response to information about a target to a threshold at which a response is initiated, at a rate that varies from trial to trial with a Gaussian distribution. Functionally, LATER may be regarded as an ideal decision mechanism incorporating prior probability, information, and criterion level or urgency; this can be tested quantitatively by seeing whether LATER accurately predicts the effects on latency distributions of manipulating these variables: in this case, information and urgency. We presented subjects with random-dot kinematograms while fixating a central LED. The information content of the display was varied by altering the proportion of the dots moving coherently together either left or right rather than randomly. As soon as subjects detected the direction of coherent movement, they made a saccade in the same direction to one of a pair of LEDs on each side of the fixation target. Subjects responded either carefully, taking time to ensure an accurate judgement, or more hastily and with less regard for accuracy. The distributions of latencies under the different combinations of conditions were found to conform to LATER's predictions. Providing more information or increasing urgency both reduce latency; but they alter the observed distributions in different ways, equivalent to increasing the mean rate of rise on the one hand or reducing the criterion level on the other. Making only simple assumptions about the underlying mechanisms, the observed changes can be accounted for quantitatively.

Saccadic countermanding: a comparison of central and peripheral stop signals.

We compared the effectiveness of central and peripheral targets in a saccadic countermanding task. Stop-signal reaction times (SSRTs) do not differ significantly for central and peripheral stop signals. Further, when central and peripheral stop signals are presented together, SSRTs behave as expected of independent processes in parallel. A linear rise-to-threshold race model (LATER) with independent go and stop processes describes the behavioural data successfully, predicting not only the latency distribution of saccades that escaped inhibition, but also the probability of successful countermanding. Central and peripheral stop signals appear to act independently and with equal effectiveness.