Invasive versus non-invasive assessment of valvuloarterial impedance in severe aortic stenosis.

BACKGROUND: As a measure of the global left ventricular afterload, valvuloarterial impedance (ZVA) can be estimated using transthoracic echocardiography (TTE) and invasive measuring methods. The objective of this study was to compare the performance of TTE in measuring ZVA with invasive haemodynamics, direct Fick and thermodilution (TD), in patients with severe aortic stenosis (AS). METHODS: This is a retrospective cohort study of 66 patients with severe AS who underwent TTE and bilateral heart catheterisation preaortic valve replacement. ZVA was calculated non-invasively from TTE and invasively using TD and Fick. The differences in measurements were estimated using a generalised estimating equation approach. The exchangeability of the measurements from different methods was evaluated under binary risk stratification rules. RESULTS: The mean±SD ZVA by TTE was 4.6±1.4 vs 4.9±1.6 by TD vs 4.3±1.2 mm Hg m2/mL by Fick. From multivariate analyses, ZVA by TTE was 5.9% (95% CI -15.0 to 2.5) lower than by TD and 5.9% (95% CI -1.5 to 12.8) higher than by Fick. At the same time, ZVA by TD was 12.5% (3.0 to 22.9) higher than with Fick. Risk classifications for ZVA-based binary decision rules showed poor agreement between TTE and invasive methods (kappa ≤0.3). CONCLUSIONS: The differences in ZVA estimates between TTE and invasive standards do not appear to exceed those between the standards. As such TTE-based estimates may be deemed acceptable as a clinical measure of global haemodynamic load. However, TTE-based and invasive measurements may not be interchangeable to identify patients at risk using binary classification rules based on ZVA.

Incidence, predictors, management and outcomes of coronary perforations.

OBJECTIVES: We examined the contemporary incidence, types, predictors, angiographic characteristics, management and outcomes of coronary perforation. BACKGROUND: Coronary perforation is a rare, but important, complication of percutaneous coronary intervention (PCI). There is lack of data on perforations stratified as large and distal vessel perforations. METHODS: Retrospective, observational cohort study of all patients who underwent PCI at a high volume, tertiary hospital between the years 2009 and 2016. Angiograms of all coronary perforation cases were reviewed to determine the mechanism, type, and management of perforation. Risk-adjusted periprocedural complication rates were compared between patients with and without coronary perforation. One-year mortality outcomes of patients with large vessel vs. distal vessel perforation were also examined. RESULTS: Coronary perforation occurred in 68 of 13,339 PCIs (0.51%) performed during the study period: 51 (75%) were large vessel perforations and 17 (25%) distal vessel perforations. Most (67%) large vessel perforations were due to balloon/stent inflation, whereas most (94%) distal vessel perforations were due to guidewire exit. Patients with coronary perforations had significantly higher risk for periprocedural complications (adjusted odds ratio 7.57; 95% CI: 4.22-13.50; P < 0.001). Only one patient with large vessel perforation required emergency cardiac surgery, yet in-hospital mortality was high with both large vessel (7.8%) and distal vessel (11.8%) perforations. CONCLUSIONS: Coronary perforation is an infrequent, but potentially severe PCI complication. Most coronary perforations are large vessel perforations. Although coronary perforations rarely lead to emergency cardiac surgery, both distal vessel and large vessel perforations are associated with high in-hospital mortality, highlighting the importance of prevention.

Assessment of individual operator performance using a risk-adjustment model for percutaneous coronary interventions.

OBJECTIVE: To investigate the applicability of the Mayo Clinic Risk Score (MCRS) in the assessment of performance metrics of individual interventional cardiologists at 3 Mayo Clinic sites. PARTICIPANTS AND METHODS: We evaluated the risk-adjusted performance of 21 interventional cardiologists who performed 8187 percutaneous coronary intervention procedures at 3 Mayo Clinic sites from January 1, 2007, through December 31, 2010. Observed mortality, major adverse cardiac events (MACEs) (eg, death, Q-wave myocardial infarction, urgent or emergent coronary artery bypass graft, and stroke), and expected risk were estimated using the MCRS. To compare individual performance against the other operators, risk estimates were recalibrated by excluding the individual performer from logistic regression models. RESULTS: The log odds ratio for observed vs estimated risk was estimated for each interventional cardiologist, and their individual effects were then plotted on a normal probability plot to identify outliers. Observed in-hospital mortality was not different than expected (1.8% vs 1.6%; P=.24); however, the postprocedural MACE rate was lower than predicted (observed, 2.7%; expected, 3.8%; P<.001). All but one interventional cardiologist had MACE and death rates within the expected variation. Detailed assessment of that operator's risk performance produced excellent outcomes (observed vs expected MACE rate, 1.0% vs 4.4%). CONCLUSION: The MCRS can serve as a tool for the assessment of performance metrics for interventional cardiologists, and risk-adjusted outcomes may serve as a better surrogate for institutional quality metrics.