R. Allan

Real-Time 3D Transesophageal Echocardiography for the Evaluation of Rheumatic Mitral Stenosis

OBJECTIVESnThe aims of this study were: 1) to assess the feasibility and reliability of performing mitral valve area (MVA) measurements in patients with rheumatic mitral valve stenosis (RhMS) using real-time 3-dimensional transesophageal echocardiography (3DTEE) planimetry (MVA(3D)); 2) to compare MVA(3D) with conventional techniques: 2-dimensional (2D) planimetry (MVA(2D)), pressure half-time (MVA(PHT)), and continuity equation (MVA(CON)); and 3) to evaluate the degree of mitral commissural fusion.nnnBACKGROUNDn3DTEE is a novel technique that provides excellent image quality of the mitral valve. Real-time 3DTEE is a relatively recent enhancement of this technique. To date, there have been no feasibility studies investigating the utility of real-time 3DTEE in the assessment of RhMS.nnnMETHODSnForty-three consecutive patients referred for echocardiographic evaluation of RhMS and suitability for percutaneous mitral valvuloplasty were assessed using 2D transthoracic echocardiography and real-time 3DTEE. MVA(3D), MVA(2D), MVA(PHT), MVA(CON), and the degree of commissural fusion were evaluated.nnnRESULTSnMVA(3D) assessment was possible in 41 patients (95%). MVA(3D) measurements were significantly lower compared with MVA(2D) (mean difference: -0.16 ± 0.22; n=25, p<0.005) and MVA(PHT) (mean difference: -0.23 ± 0.28 cm(2); n=39, p<0.0001) but marginally greater than MVA(CON) (mean difference: 0.05 ± 0.22 cm(2); n=24, p=0.82). MVA(3D) demonstrated best agreement with MVA(CON) (intraclass correlation coefficient [ICC] 0.83), followed by MVA(2D) (ICC 0.79) and MVA(PHT) (ICC 0.58). Interobserver and intraobserver agreement was excellent for MVA(3D), with ICCs of 0.93 and 0.96, respectively. Excellent commissural evaluation was possible in all patients using 3DTEE. Compared with 3DTEE, underestimation of the degree of commissural fusion using 2D transthoracic echocardiography was observed in 19%, with weak agreement between methods (κ<0.4).nnnCONCLUSIONSnMVA planimetry is feasible in the majority of patients with RhMS using 3DTEE, with excellent reproducibility, and compares favorably with established methods. Three-dimensional transesophageal echocardiography allows excellent assessment of commissural fusion.

Modifying fluoroscopic views reduces operator radiation exposure during coronary angioplasty

OBJECTIVESnThis three-part study examined the feasibility of reducing operator radiation exposure during coronary angioplasty.nnnBACKGROUNDnAs case loads and complexity increase, some cardiologists are receiving increasing radiation scatter doses. Techniques to reduce this are therefore becoming more important.nnnMETHODSnFirst, the determinants of the operator dose were assessed by measuring the differences in scatter dose with different camera views. The relative contribution of fluoroscopy as opposed to cine was then quantified. Finally, operators were provided with these data, and subsequent changes in technique were evaluated.nnnRESULTSnLeft anterior oblique views resulted in 2.6 to 6.1 times the operator dose of equivalently angled right anterior oblique views. Increasing steepness of the left anterior oblique view also resulted in a progressive increase in operator dose, with left anterior oblique 90 degrees causing eight times the dose of left anterior oblique 30 degrees and three times that of left anterior oblique 60 degrees. In the 45 coronary angioplasty cases prospectively analyzed, fluoroscopy was found to be a greater source of total radiation than cine by a 6.3:1 ratio (range 1.1 to 15.8). Once operators were made aware of the importance of left anterior oblique fluoroscopy, there was a marked reduction in its use. When this was not feasible, there was a reduction in the steepness of the angulation. Left anterior oblique fluoroscopy during angioplasty of the left anterior descending and circumflex coronary arteries was reduced from 40% of total screening time to approximately 5%, and left anterior oblique angulation for fluoroscopy during angioplasty of the right coronary artery decreased from 43.6 degrees (+/- 9.1 degrees) to 29.4 degrees (+/- 2.2 degrees). Success rates (90% vs. 89%) and screening times (19.5 vs. 20.7 min) remained unchanged in 200 coronary angioplasties performed after the study. Average operator radiation dose (measured by radiation badges worn under lead at waist level) was reduced from 32.6 to 14.3 microSv/operator per week despite a slight increase in case load.nnnCONCLUSIONSnFluoroscopy is the major source of total radiation exposure during coronary angioplasty, with left anterior oblique views providing the highest dose. Modification of views is feasible and will result in significant reduction of operator radiation dose.

Prognostic Significance of Peri-procedural Myocardial Infarction in the Era of High Sensitivity Troponin: A Validation of the Joint ACCF/AHA/ESC/WHF Universal Definition of Type 4a Myocardial Infarction with High Sensitivity Troponin T

AIMSnThis study aims to validate the joint ACCF/AHA/ESC/WHF Universal Definition of peri-procedural myocardial infarction (PMI) with high sensitivity troponin T (hsTnT).nnnMETHODSnA retrospective cohort study encompassing patients admitted to our institution between May 2012 and April 2013 was performed.nnnRESULTSn630 patients underwent percutaneous coronary interventions during the study period. Among them, 459 patients met the inclusion criteria and were eligible for analyses. 76.9% of these patients were male, while the mean age was 68.6. PMI was observed in 4.3% of the patients based on the Universal Definition. The predictors of PMI were chronic kidney disease (OR: 3.0, p=0.026), family history of cardiovascular disease (OR: 2.7, p=0.043) and use of IIb/IIIa inhibitors (OR 4.2, p=0.01). MACE was reported in 4.4% of the patients at 12 months, and was significantly and independently associated with PMI (OR 7.3, p=0.003) in a multivariate model which accounted for lesion complexity, patients baseline clinical information, dual-antiplatelet status at follow-up and various procedural characteristics. The post-procedural hsTnT was much higher in those who suffered MACE than those who did not (156 v.s. 43 ng/L, p<0.001).nnnCONCLUSIONnPMI as defined by the current Universal Definition using hsTnT is an independent predictor of adverse clinical outcome at 12 months in patients undergoing PCI. Accordingly, PMI remains a clinically relevant factor in current practice and should be considered a key outcome measure in clinical trials and a potential target for therapy.

Activated clotting time differential is a superior method of monitoring anticoagulation following coronary angioplasty

The standard high-range activated clotting time (sHR ACT) is used to monitor anticoagulation postangioplasty (PTCA), but may be unreliable. We assessed the accuracy of a new method we termed the ACT differential (ACT Diff), obtained by measuring the difference between an sHR ACT and a heparinase ACT from the same sample. Heparinase removes heparin from its sample and provides a current heparin-free baseline. For phase 1 of the study, the sHR ACT, ACT Diff, and laboratory APTT were measured in 250 samples from 75 PTCA patients. In 125 samples with an APTT prolonged but within measurement range, linear regression against the APTT was performed. The correlation coefficient was 0.74 for the ACT Diff and 0.24 for the sHR ACT. An ACT Diff of 15-25 sec was found to equal an APTT of 2.5-3.5 x control. In 50 samples with a normal activated partial thromboplastin time (APT), there was good differentiation by the ACT Diff of results from those adequately heparinized, with a value of 0.9 +/- 4.4 sec. The sHR ACT was 114 +/- 15.5 sec, and could not reliably distinguish between anticoagulated and nonanticoagulated samples. In 75 samples obtained with a high APTT (above measurement range), the ACT Diff was > 30 sec in 95% of samples, and again this allowed differentiation from therapeutic samples. The equivalent sHR ACT was 148 sec, and could not reliably distinguish between anticoagulated and overanticoagulated samples as the ACT Diff could. In phase 2, to examine the clinical usefulness of the ACT Diff, 286 patients were managed post-PTCA by starting heparin when ACT Diff fell to < 50 sec, maintaining ACT Diff at 15-25 sec during heparin infusions, and following cessation of heparin, by removing sheaths when the ACT Diff was < 7 sec. These patients were compared to a control group of 250 patients. Major bleeding (5% vs. 0.5%, P < 0.005) and minor bleeding (30% vs. 13%, P < 0.001) were significantly reduced in the group managed using the ACT Diff. The reduction in bleeding was thought to be due to the rapid availability of reliable results. Abrupt closure was low in both groups (0% with ACT Diff vs. 0.8%). No other thrombotic events occurred. Following phases 1 and 2, the ACT Diff replaced the APTT in all PTCA patients at this institution. In the 18 mo from July 1993, 1,104 patients were managed this way. Incidence of major bleeding (0.2%), transfusion requirement (0.1%), false anneurysm (0.6%), and abrupt closure during heparin infusion (0.1%) remained low. In conclusion, the ACT Diff is more accurate than an sHR ACT, and its clinical use in PTCA patients is associated with a very low incidence of complications from anticoagulation. Its routine use should be considered by units unable to obtain rapid APTT results.

Balloon Aortic Valvuloplasty in The Transcatheter Valve Era: Single Centre Indications And Early Safety Data in A High Risk Population

BACKGROUNDnThe introduction of transcatheter aortic valve implantation (TAVI) has generated a renewed interest in the techniques available to treat high-risk patients with severe aortic stenosis (AS). We report our single centre experience with balloon aortic valvuloplasty (BAV) focussing on indications, procedural success and 30-day outcomes.nnnMETHODSnWe retrospectively reviewed all patients that underwent BAV procedures at our institution between August 2012 and August 2014. Procedural success and complications were adjudicated according to VARC-2 criteria.nnnRESULTSnFifty-one consecutive adult patients with severe symptomatic AS underwent a total of 55 BAV procedures. The patients had a mean age of 88±5.7 years and all had extensive comorbidities with a high surgical risk (mean logistic EuroSCORE of 25.22%±14.5%). Indications for BAV included palliation of symptoms n=42 (76%); bridge to definitive valve replacement (n=6, 11%); and evaluation of response (n=6, 11%). The procedure was completed in all patients with no intraprocedural deaths (within 24hours) and low 30-day mortality at 3.9% (n=2). Minor vascular complications occurred in 11.8% (n=6), whilst permanent pacemaker implantation was required in 5.8% (n=3). There were no cases of myocardial infarction, stroke, tamponade, severe aortic regurgitation or major vascular complications during 30-day follow-up.nnnCONCLUSIONSnBalloon aortic valvuloplasty may be performed safely and effectively with high procedural success and low 30-day complications, even in a very high-risk and elderly cohort of patients in whom the role of TAVI is uncertain or inappropriate.