Left Ventricular Unloading Is Associated With Lower Mortality in Patients With Cardiogenic Shock Treated With Venoarterial Extracorporeal Membrane Oxygenation: Results From an International, Multicenter Cohort Study.

BACKGROUND: Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly used to treat cardiogenic shock. However, VA-ECMO might hamper myocardial recovery. The Impella unloads the left ventricle. This study aimed to evaluate whether left ventricular unloading in patients with cardiogenic shock treated with VA-ECMO was associated with lower mortality. METHODS: Data from 686 consecutive patients with cardiogenic shock treated with VA-ECMO with or without left ventricular unloading using an Impella at 16 tertiary care centers in 4 countries were collected. The association between left ventricular unloading and 30-day mortality was assessed by Cox regression models in a 1:1 propensity score-matched cohort. RESULTS: Left ventricular unloading was used in 337 of the 686 patients (49%). After matching, 255 patients with left ventricular unloading were compared with 255 patients without left ventricular unloading. In the matched cohort, left ventricular unloading was associated with lower 30-day mortality (hazard ratio, 0.79 [95% CI, 0.63-0.98]; P=0.03) without differences in various subgroups. Complications occurred more frequently in patients with left ventricular unloading: severe bleeding in 98 (38.4%) versus 45 (17.9%), access site-related ischemia in 55 (21.6%) versus 31 (12.3%), abdominal compartment in 23 (9.4%) versus 9 (3.7%), and renal replacement therapy in 148 (58.5%) versus 99 (39.1%). CONCLUSIONS: In this international, multicenter cohort study, left ventricular unloading was associated with lower mortality in patients with cardiogenic shock treated with VA-ECMO, despite higher complication rates. These findings support use of left ventricular unloading in patients with cardiogenic shock treated with VA-ECMO and call for further validation, ideally in a randomized, controlled trial.

Impact of residual coronary atherosclerosis on transfemoral transcatheter aortic valve replacement.

OBJECTIVES: This study reports on the clinical effects of complete vs incompletely revascularized coronary artery disease on transcatheter aortic valve replacement (TAVR). BACKGROUND: There is a high prevalence of active coronary artery disease (CAD) in patients undergoing TAVR but preemptive revascularization remains controversial. METHODS: Patients were categorized into three cohorts: complete revascularization (CR), incomplete revascularization of a major epicardial artery (IR Major), and incomplete revascularization of a minor epicardial artery only (IR Minor). When feasible, SYNTAX scoring was performed for exploratory analysis. Analyses were performed using Cox proportional hazard models and Kaplan-Meier method. RESULTS: A total of 323 patients with active CAD were included. Adjusted outcomes showed that patients with IR Major had increased incidence of acute myocardial infarction (AMI) or revascularization compared with those in the CR cohort (HR 3.72, P = 0.048). No difference was noted in all-cause mortality or all-cause readmission rates. Exploratory secondary analysis with residual SYNTAX scores showed a significant interaction between disease burden and AMI/revascularization, as well as all-cause readmission. All-cause mortality remained unaffected based on residual SYNTAX scores. CONCLUSIONS: This is a retrospective single-center study reporting on pre-TAVR revascularization outcomes in patients with active CAD. In this analysis, we found that patients undergoing TAVR benefited from achieving complete revascularization to abate future incidence of AMI/revascularization. Despite this finding, all-cause mortality remained unaffected. Future efforts should focus on the role of functional assessment of the coronaries, as well as the long-term effects of complete revascularization in a larger patient cohort.

Comprehensive Assessment of Coronary Artery Disease by Using First-Pass Analysis Dynamic CT Perfusion: Validation in a Swine Model.

Purpose To retrospectively validate a first-pass analysis (FPA) technique that combines computed tomographic (CT) angiography and dynamic CT perfusion measurement into one low-dose examination. Materials and Methods The study was approved by the animal care committee. The FPA technique was retrospectively validated in six swine (mean weight, 37.3 kg ± 7.5 [standard deviation]) between April 2015 and October 2016. Four to five intermediate-severity stenoses were generated in the left anterior descending artery (LAD), and 20 contrast material-enhanced volume scans were acquired per stenosis. All volume scans were used for maximum slope model (MSM) perfusion measurement, but only two volume scans were used for FPA perfusion measurement. Perfusion measurements in the LAD, left circumflex artery (LCx), right coronary artery, and all three coronary arteries combined were compared with microsphere perfusion measurements by using regression, root-mean-square error, root-mean-square deviation, Lin concordance correlation, and diagnostic outcomes analysis. The CT dose index and size-specific dose estimate per two-volume FPA perfusion measurement were also determined. Results FPA and MSM perfusion measurements (PFPA and PMSM) in all three coronary arteries combined were related to reference standard microsphere perfusion measurements (PMICRO), as follows: PFPA_COMBINED = 1.02 PMICRO_COMBINED + 0.11 (r = 0.96) and PMSM_COMBINED = 0.28 PMICRO_COMBINED + 0.23 (r = 0.89). The CT dose index and size-specific dose estimate per two-volume FPA perfusion measurement were 10.8 and 17.8 mGy, respectively. Conclusion The FPA technique was retrospectively validated in a swine model and has the potential to be used for accurate, low-dose vessel-specific morphologic and physiologic assessment of coronary artery disease. © RSNA, 2017.

The Implementation and Outcomes of a Nurse-Run Extracorporeal Membrane Oxygenation Program, a Retrospective Single-Center Study.

Due to a shortage of perfusionists and increasing utilization of extracorporeal membrane oxygenation in the United States, many programs are training nurses as bedside extracorporeal membrane oxygenation specialists (i.e., nurse-run extracorporeal membrane oxygenation). Our objective was to evaluate if a nurse-run extracorporeal membrane oxygenation program has noninferior survival to discharge and complication rates compared with a perfusionist-run extracorporeal membrane oxygenation program. Additionally, to sought to describe increases in extracorporeal membrane oxygenation capacity and the potential for cost savings by implementing a nurse-run extracorporeal membrane oxygenation program.

Statin effect on coronary calcium distribution, mass and volume scores and associations with immune activation among HIV+ persons on antiretroviral therapy.

BACKGROUND: Inflammation has been associated with whole heart coronary artery calcification (CAC) among people with HIV (PWH) on antiretroviral therapy (ART); however, prior studies have not evaluated the distribution of calcium or separated mass versus volume scores, which are differentially associated with clinical events in the general population. Statins may also have a greater effect on CAC mass compared with volume. METHODS: 147 PWH were randomized 1:1 to rosuvastatin 10 mg or placebo and followed for 96 weeks. We re-analysed coronary calcium scans from 0, 48 and 96 weeks to determine mass and volume scores and measures of CAC diffusivity. Mixed effects models and generalized estimating equations were used to examine longitudinal associations of CAC with treatment and biomarkers. RESULTS: Median age at study entry was 46 years; 78% were male and 68% African American. Median CD4+ was 613 and half were on protease inhibitors. Randomization to statin therapy was not associated with a change in mass score, volume score, number of involved vessels or diffusivity index (all P>0.1). Soluble CD14 was associated with the presence of CAC (P=0.05) and borderline associated with number of involved vessels (P=0.07) across all three time points. CONCLUSIONS: In PWH on ART, moderate intensity rosuvastatin does not appear to have a significant effect on volume, mass or regional distribution of CAC over 96 weeks. We extend previous cross-sectional observations to show that soluble CD14 is associated with whole heart CAC over time and independently of age and systolic blood pressure.

Transcatheter Valve Implantation for Failed Surgical Aortic and Mitral Bioprostheses: A Single-Center Experience.

OBJECTIVES: We share our center's experience with the use of transcatheter valvular therapies in the setting of failed bioprostheses. BACKGROUND: As medicine continues to advance, the lifespan of individuals continues to increase, and current surgical valvular therapies begin to degrade prior to a person's end of life. It is important to evaluate the efficacy and durability of transcatheter valves within failed surgical bioprostheses. METHODS: Baseline characteristics, periprocedural complications, and long-term outcomes were collected and assessed in patients who received transcatheter valves for failing surgical aortic valve bioprostheses and mitral valve and ring bioprostheses from March 2011 to July 2018. RESULTS: From our cohort of 1048 patients, we identified 45 individuals (4.3%) who underwent transcatheter replacement of a failed bioprosthetic valve or ring. Mean age at presentation was 80.8 ± 10.7 years and 75.5 ± 9.3 years, mean STS score was 9.3 ± 5.1 and 13.3 ± 8.7, and mean time to failure was 12.0 ± 5.2 years and 7.3 ± 4.5 years for aortic and mitral positions, respectively. At 1 year, time to event analysis suggested a 16.4% mortality rate for aortic replacement and 12.8% mortality rate for mitral replacement. CONCLUSIONS: We demonstrate outcomes from one of the largest single-center United States based cohorts of transcatheter replacements of failed surgical bioprostheses. Our center has demonstrated that it is feasible to pursue the replacement of failed surgical bioprostheses in the aortic and mitral positions with transcatheter valves given appropriate patient selection.

A phantom based evaluation of vessel lumen area quantification for coronary CT angiography.

Coronary computed tomography (CT) angiography is a noninvasive method for visualizing coronary artery disease. However, coronary CT angiography is limited in assessment of stenosis severity by the partial volume effect and calcification. Therefore, an accurate method for assessment of stenosis severity is needed. A 10 cm diameter cylindrical Lucite phantom with holes in the range of 0.4-4.5 mm diameter was fitted in a chest phantom. The holes were filled with an iodine solution of 8 mg/mL. To simulate coronary artery disease, different levels of stenosis were created by inserting Lucite rods into the holes with diameter range of 2-4.5 mm. The resulting lumen cross sectional areas ranged from 1.4 to 12.3 mm2. To simulate arterial calcification, calcium hydroxyapatite rods were inserted into the holes with diameter range of 2-4.5 mm. Images of the phantoms were acquired at 100 kVp using a 320-slice CT scanner. A maual and a semi-automated technique based on integrated Hounsfield units was used to calculate vessel cross-sectional area. There was an excellent correlation between the measured and the known cross-sectional area for both normal and stenotic vessels using the manual and the semi-automated techniques. However, the overall measurement error for the manual method was more than twice as compared with the integrated HU technique. Determination of vessel lumen area using the semi-automated integrated Hounsfield unit technique yields more than a factor of two improvement in precision and accuracy as compared to the existing manual technique for vessels with and without stenosis. This technique can also be used to accurately measure arterial cross-sectional area in the presence of coronary calcification.

Even Mended Hearts Can Break: Takotsubo After Transcatheter Mitral Valve Replacement.

Transcatheter mitral valve replacement represents an innovative interventional technique for implanting a new mitral prosthesis without surgery. Although technical success is high, post-procedural issues and complications may occur. This report emphasizes the importance of considering alternative cardiac pathologies that may be seen post valvular interventions. (Level of Difficulty: Beginner.).

Outcomes Among Patients With Heart Failure With Reduced Ejection Fraction Undergoing Transcatheter Aortic Valve Replacement: Minimally Invasive Strategy Versus Conventional Strategy.

OBJECTIVES: To investigate the effect of TAVR technique on in-hospital and 30-day outcomes in patients with aortic stenosis (AS) and reduced ejection fraction (EF). BACKGROUND: Patients with AS and concomitant low EF may be at risk for adverse hemodynamic effects from general anesthesia utilized in transcatheter aortic valve replacement (TAVR) via the conventional strategy (CS). These patients may be better suited for the minimally invasive strategy (MIS), which employs conscious sedation. However, data are lacking that compare MIS to CS in patients with AS and concomitant low EF. METHODS: In this retrospective study, we identified all patients with low EF (<50%) undergoing transfemoral MIS-TAVR vs CS-TAVR between March 2011 and May 2018. Our primary endpoint was defined as the composite of in-hospital mortality and major periprocedural bleeding or vascular complications. RESULTS: Two hundred and seventy patients had EF <50%, while 154 patients had EF ≤35%. Overall, a total of 236 patients were in the MIS group and 34 were in the CS group. Baseline characteristics between the two groups were similar except for Society of Thoracic Surgeons (STS) score (MIS 8.4 ± 5.1 vs CS 11.7 ± 6.8; P<.01). There were no differences between the two groups in incidence of the primary endpoint (MIS 5.5% vs CS 8.8%; odds ratio for MIS, 0.60; 95% confidence interval, 0.16-2.23; P=.45). CONCLUSIONS: In patients with severe AS and reduced EF, MIS was not associated with adverse in-hospital or 30-day clinical outcomes compared with CS. In these patients, MIS may be a suitable alternative to CS without compromising clinical outcomes.

Short-Term and Long-Term Outcomes of Patients Undergoing Urgent Transcatheter Aortic Valve Replacement Under a Minimalist Strategy.

OBJECTIVES: Urgent transcatheter aortic valve replacement (TAVR) is associated with worse short-term outcomes compared with elective TAVR; however, little is known about long-term outcomes or the safety of the minimalist strategy in this setting. This study investigated the short-term and long-term outcomes of urgent TAVR compared with elective TAVR under a minimalist strategy (transfemoral [TF] approach with conscious sedation and no transesophageal echocardiography guidance). METHODS: After excluding 2 emergent patients requiring immediate procedures, a total of 474 consecutive patients underwent elective TF-TAVR (396 patients; 83.6%) or urgent TF-TAVR (78 patients; 16.4%). Urgent TAVR was defined as a procedure performed in the same hospitalization in patients emergently admitted due to cardiac arrest, severe acute decompensated heart failure, acute coronary syndrome, or repeated syncopal episodes. RESULTS: A minimalist approach was used in 77 patients (98.7%) undergoing urgent TAVR and in 392 patients (99.0%) undergoing elective TAVR (P=.59). Urgent TAVR had similar procedure-related complications, such as stroke, myocardial infarction, bleeding or vascular complications, and in-hospital mortality compared with elective TAVR (mortality, 1.3% vs 0.8%; P=.51) with no intraprocedural cross-over from conscious sedation to general anesthesia. However, 30-day and 1-year survival rates were reduced in patients undergoing urgent TAVR. After adjustment with baseline and procedural factors, urgent TAVR remained significantly predictive of 1-year mortality (adjusted hazard ratio, 2.26; 95% confidence interval, 1.16-4.23; P=.01). CONCLUSIONS: Urgent minimalist TAVR can be safely performed with favorable in-hospital outcomes, while increased 30-day and 1-year mortality rates suggest the importance of appropriate diagnosis and timely treatment of severe aortic stenosis.

Feasibility and Safety of Adopting Next-Day Discharge as First-Line Option After Transfemoral Transcatheter Aortic Valve Replacement.

OBJECTIVES: Data on next-day discharge (NDD) after transcatheter aortic valve replacement (TAVR) are limited. This study investigated the feasibility and safety of NDD as a first-line option (the very-early discharge [VED] strategy) compared with the early-discharge (ED) strategy (2-3 days as a first-line option) after TAVR. METHODS: We reviewed 611 consecutive patients who had minimalist TAVR (transfemoral approach under conscious sedation) and no in-hospital mortality; a total of 418 patients underwent ED strategy (since December 2013) and 193 patients underwent VED strategy (as part of a hospital initiative to reduce length of stay, since August 2016). NDD in the VED strategy was performed with heart team consensus in patients without significant complications. The primary outcome was a composite of 30-day all-cause mortality/rehospitalization. RESULTS: Sixty-five patients (33.7%) in the VED strategy and 10 patients (2.4%) in the ED strategy were discharged the next day (P<.001). NDD patients had received balloon-expandable (n = 30) or self-expanding valves (n = 45) and showed a similar primary outcome rate compared with non-NDD patients. After adjustment using propensity score matching (172 pairs), post-TAVR length of stay was significantly shorter in the VED group (3.2 ± 3.1 days) than in the ED group (3.5 ± 2.7 days; P<.01). The primary outcome did not differ between the two groups (7.0% vs 11.6%; P=.14), with comparable 30-day mortality rate (1.2% vs 2.3%; P=.68) and rehospitalization rate (5.8% vs 11.1%; P=.08). CONCLUSIONS: Utilization of NDD as a first-line option after minimalist TAVR is feasible and safe, and leads to further reduction in length of stay compared with an ED strategy.

Simultaneous Venoarterial Extracorporeal Membrane Oxygenation and Percutaneous Left Ventricular Decompression Therapy with Impella Is Associated with Improved Outcomes in Refractory Cardiogenic Shock.

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) has been used for refractory cardiogenic shock; however, it is associated with increased left ventricular afterload. Outcomes associated with the combination of a percutaneous left ventricular assist device (Impella) and VA-ECMO remains largely unknown. We retrospectively reviewed patients treated for refractory cardiogenic shock with VA-ECMO (2014-2016). The primary outcome was all-cause mortality within 30 days of VA-ECMO implantation. Secondary outcomes included duration of support, stroke, major bleeding, hemolysis, inotropic score, and cardiac recovery. Outcomes were compared between the VA-ECMO cohort and VA-ECMO + Impella (ECPELLA cohort). Sixty-six patients were identified: 36 VA-ECMO and 30 ECPELLA. Fifty-eight percent of VA-ECMO patients (n = 21) had surgical venting, as compared to 100% of the ECPELLA cohort (n = 30) which had Impella (±surgical vent). Both cohorts demonstrated relatively similar baseline characteristics except for higher incidence of ST-elevation myocardial infarction (STEMI) and percutaneous coronary intervention (PCI) in the ECPELLA cohort. Thirty-day all-cause mortality was significantly lower in the ECPELLA cohort (57% vs. 78%; hazard ratio [HR] 0.51 [0.28-0.94], log rank p = 0.02), and this difference remained intact after correcting for STEMI and PCI. No difference between secondary outcomes was observed, except for the inotrope score which was greater in VA-ECMO group by day 2 (11 vs. 0; p = 0.001). In the largest US-based retrospective study, the addition of Impella to VA-ECMO for patients with refractory cardiogenic shock was associated with lower all-cause 30 day mortality, lower inotrope use, and comparable safety profiles as compared with VA-ECMO alone.

Impact of Right Ventricular Pacing in Patients Who Underwent Implantation of Permanent Pacemaker After Transcatheter Aortic Valve Implantation.

Atrioventricular conduction disturbances requiring implantation of permanent pacemaker (PPM) are a common complication following transcatheter aortic valve implantation (TAVI). Previous registry data are conflicting but suggestive of an increased risk in heart failure admissions in the post-TAVI PPM cohort. Given the expanding use of TAVI, the present study evaluates the effects of chronic right ventricular pacing (RV pacing) in post-TAVI patients. This is a single-center study of 672 patients who underwent TAVI from 2011 to 2017 of which 146 underwent PPM. Follow-up 1-year post-TAVI outcome data were available for 55 patients and were analyzed retrospectively. Patients who underwent PPM were more likely to have heart failure admissions (17.1% vs 10.1%; hazard ratio [HR] 1.70; 95% confidence interval [CI] 1.10 to 2.64; p 0.019) and a trend toward increased mortality (21.9% vs 15.4%; HR 1.42; 95% CI 0.99 to 2.05; p 0.062). At 1-year follow-up, 30 of 55 (54.5%) patients demonstrated >40% RV pacing. Compared with patients who had <40% RV pacing, those with >40% RV pacing were more likely to have heart failure admissions (8% vs 40%; HR 5.0; 95% CI 1.23 to 20.27; p 0.007) and demonstrated a trend toward increased mortality (12% vs 33.3%; HR 2.78; 95% CI 0.86 to 9.00; p 0.064). This is suggestive that the post-TAVI PPM cohort is particularly sensitive to chronic RV pacing.

Accurate quantification of vessel cross-sectional area using CT angiography: a simulation study.

Coronary computed tomography (CT) angiography is a noninvasive method for visualizing coronary atherosclerosis. However, CT angiography is limited in assessment of stenosis severity by the partial volume effect and calcification. Therefore, a quantitative method for assessment of stenosis severity is needed. Polyenergetic fan beam CT simulations were performed to match the geometry of a 320-slice CT scanner. Contrast-enhanced vessel lumens were modeled as 8 mg/ml Iodine solution against a lipid background. Normal vessels were simulated by circles with diameters in the range of 0.1-3 mm. To simulate lesions, 2, 3, and 4 mm diameter vessels were simulated with area stenoses in a range of 10-90 %. The occlusion was created by a circular region of lipid placed within the lumen resulting in a crescent shaped lumen. Each vessel was simulated three times to obtain multiple noise realizations for a total of 126 vessels. Two trained readers performed manual cross-sectional area measurements in simulated normal and stenotic vessels. A new, semi-automated technique based on integrated Hounsfield units was also used to calculate vessel cross-sectional area. There was an excellent correlation between the measured and the known cross-sectional area for both normal and stenotic vessels using the manual and the semi-automated techniques. However, the overall measurement error for the manual method was more than twice as compared with the integrated HU technique. Determination of vessel cross-sectional area using the semi-automated integrated Hounsfield unit technique yields more than a factor of two improvement in accuracy as compared to the existing manual technique for vessels with and without stenosis. This technique can also be used to correct for the effect of coronary calcification.

Functional Assessment of Coronary Artery Disease Using Whole-Heart Dynamic Computed Tomographic Perfusion.

BACKGROUND: Computed tomographic (CT) angiography is an important tool for the evaluation of coronary artery disease but often correlates poorly with myocardial ischemia. Current dynamic CT perfusion techniques can assess ischemia but have limited accuracy and deliver high radiation dose. Therefore, an accurate, low-dose, dynamic CT perfusion technique is needed. METHODS AND RESULTS: A total of 20 contrast-enhanced CT volume scans were acquired in 5 swine (40±10 kg) to generate CT angiography and perfusion images. Varying degrees of stenosis were induced using a balloon catheter in the proximal left anterior descending coronary artery, and a pressure wire was used for reference fractional flow reserve (FFR) measurement. Perfusion measurements were made with only 2 volume scans using a new first-pass analysis (FPA) technique and with 20 volume scans using an existing maximum slope model (MSM) technique. Perfusion (P) and FFR measurements were related by PFPA=1.01 FFR-0.03 (R2=0.85) and PMSM=1.03 FFR-0.03 (R2=0.80) for FPA and MSM techniques, respectively. Additionally, the effective radiation doses were calculated to be 2.64 and 26.4 mSv for FPA and MSM techniques, respectively. CONCLUSIONS: A new FPA-based dynamic CT perfusion technique was validated in a swine animal model. The results indicate that the FPA technique can potentially be used for improved anatomical and functional assessment of coronary artery disease at a relatively low radiation dose.

Dynamic CT perfusion measurement in a cardiac phantom.

Widespread clinical implementation of dynamic CT myocardial perfusion has been hampered by its limited accuracy and high radiation dose. The purpose of this study was to evaluate the accuracy and radiation dose reduction of a dynamic CT myocardial perfusion technique based on first pass analysis (FPA). To test the FPA technique, a pulsatile pump was used to generate known perfusion rates in a range of 0.96-2.49 mL/min/g. All the known perfusion rates were determined using an ultrasonic flow probe and the known mass of the perfusion volume. FPA and maximum slope model (MSM) perfusion rates were measured using volume scans acquired from a 320-slice CT scanner, and then compared to the known perfusion rates. The measured perfusion using FPA (P(FPA)), with two volume scans, and the maximum slope model (P(MSM)) were related to known perfusion (P(K)) by P(FPA) = 0.91P(K) + 0.06 (r = 0.98) and P(MSM) = 0.25P(K) - 0.02 (r = 0.96), respectively. The standard error of estimate for the FPA technique, using two volume scans, and the MSM was 0.14 and 0.30 mL/min/g, respectively. The estimated radiation dose required for the FPA technique with two volume scans and the MSM was 2.6 and 11.7-17.5 mSv, respectively. Therefore, the FPA technique can yield accurate perfusion measurements using as few as two volume scans, corresponding to approximately a factor of four reductions in radiation dose as compared with the currently available MSM. In conclusion, the results of the study indicate that the FPA technique can make accurate dynamic CT perfusion measurements over a range of clinically relevant perfusion rates, while substantially reducing radiation dose, as compared to currently available dynamic CT perfusion techniques.