Development of a Novel Score to Predict Urgent Mechanical Circulatory Support in Chronic Total Occlusion Percutaneous Coronary Intervention.

Estimating the likelihood of urgent mechanical circulatory support (MCS) can facilitate procedural planning and clinical decision-making in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We analyzed 2,784 CTO PCIs performed between 2012 and 2021 at 12 centers. The variable importance was estimated by a bootstrap applying a random forest algorithm to a propensity-matched sample (a ratio of 1:5 matching cases with controls on center). The identified variables were used to predict the risk of urgent MCS. The performance of the risk model was assessed in-sample and on 2,411 out-of-sample procedures that did not require urgent MCS. Urgent MCS was used in 62 (2.2%) of cases. Patients who required urgent MCS were older (70 [63 to 77] vs 66 [58 to 73] years, p = 0.003) compared with those who did not require urgent MCS. Technical (68% vs 87%, p <0.001) and procedural success (40% vs 85%, p <0.001) was lower in the urgent MCS group compared with cases that did not require urgent MCS. The risk model for urgent MCS use included retrograde crossing strategy, left ventricular ejection fraction, and lesion length. The resulting model demonstrated good calibration and discriminatory capacity with the area under the curve (95% confidence interval) of 0.79 (0.73 to 0.86) and specificity and sensitivity of 86% and 52%, respectively. In the out-of-sample set, the specificity of the model was 87%. The Prospective Global Registry for the Study of Chronic Total Occlusion Intervention CTO MCS score can help estimate the risk of urgent MCS use during CTO PCI.

Sex Differences in pLVAD-Assisted High-Risk Percutaneous Coronary Intervention: Insights From the PROTECT III Study.

BACKGROUND: Prior studies have found that female patients have worse outcomes following high-risk percutaneous coronary intervention (HRPCI). OBJECTIVES: The authors sought to evaluate sex-based differences in patient and procedural characteristics, clinical outcomes, and safety of Impella-supported HRPCI in the PROTECT III study. METHODS: We evaluated sex-based differences in the PROTECT III study; a prospective, multicenter, observational study of patients undergoing Impella-supported HRPCI. The primary outcome was 90-day major adverse cardiac and cerebrovascular events (MACCE)-the composite of all-cause death, myocardial infarction, stroke/transient ischemic attack, and repeat revascularization. RESULTS: From March 2017 to March 2020, 1,237 patients (27% female) were enrolled. Female patients were older, more often Black, more often anemic, and had more prior strokes and worse renal function, but higher ejection fractions compared to male patients. Preprocedural SYNTAX score was similar between sexes (28.0 ± 12.3). Female patients were more likely to present with acute myocardial infarction (40.7% vs 33.2%; P = 0.02) and more often had femoral access used for PCI and nonfemoral access used for Impella device implantation. Female patients had higher rates of immediate PCI-related coronary complications (4.2% vs 2.1%; P = 0.004) and a greater drop in SYNTAX score post-procedure (-22.6 vs -21.0; P = 0.04). There were no sex differences in 90-day MACCE, vascular complications requiring surgery, major bleeding, or acute limb ischemia. After adjustment using propensity matching and multivariable regression, immediate PCI-related complications was the only safety or clinical outcome that was significantly different by sex. CONCLUSIONS: In this study, rates of 90-day MACCE compared favorably to prior cohorts of HRPCI patients and there was no significant sex differences. (The PROTECT III Study is a substudy of The Global cVAD Study [cVAD]; NCT04136392).

Angiographic Features and Clinical Outcomes of Balloon Uncrossable Lesions during Chronic Total Occlusion Percutaneous Coronary Intervention.

Background: Balloon uncrossable lesions are defined as lesions that cannot be crossed with a balloon after successful guidewire crossing. Methods: We analyzed the association between balloon uncrossable lesions and procedural outcomes of 8671 chronic total occlusions (CTOs) percutaneous coronary interventions (PCIs) performed between 2012 and 2022 at 41 centers. Results: The prevalence of balloon uncrossable lesions was 9.2%. The mean patient age was 64.2 ± 10 years and 80% were men. Patients with balloon uncrossable lesions were older (67.3 ± 9 vs. 63.9 ± 10, p < 0.001) and more likely to have prior coronary artery bypass graft surgery (40% vs. 25%, p < 0.001) and diabetes mellitus (50% vs. 42%, p < 0.001) compared with patients who had balloon crossable lesions. In-stent restenosis (23% vs. 16%. p < 0.001), moderate/severe calcification (68% vs. 40%, p < 0.001), and moderate/severe proximal vessel tortuosity (36% vs. 25%, p < 0.001) were more common in balloon uncrossable lesions. Procedure time (132 (90, 197) vs. 109 (71, 160) min, p < 0.001) was longer and the air kerma radiation dose (2.55 (1.41, 4.23) vs. 1.97 (1.10, 3.40) min, p < 0.001) was higher in balloon uncrossable lesions, while these lesions displayed lower technical (91% vs. 99%, p < 0.001) and procedural (88% vs. 96%, p < 0.001) success rates and higher major adverse cardiac event (MACE) rates (3.14% vs. 1.49%, p < 0.001). Several techniques were required for balloon uncrossable lesions. Conclusion: In a contemporary, multicenter registry, 9.2% of the successfully crossed CTOs were initially balloon uncrossable. Balloon uncrossable lesions exhibited lower technical and procedural success rates and a higher risk of complications compared with balloon crossable lesions.

Use of Mechanical Circulatory Support in Chronic Total Occlusion Percutaneous Coronary Intervention.

The use of mechanical circulatory support (MCS) in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study. We analyzed the clinical and angiographic characteristics, and procedural outcomes of 7,171 CTO PCIs performed between 2012 and 2021 at 35 international centers. Mean age was 64.5 ± 10 years, mean left ventricular ejection fraction was 50 ± 13%. MCS was used in 4.5%, prophylactically in 78.7%, and urgently in 21.3%. The most common type of MCS overall was Impella CP (Abiomed) (55.5%), followed by intra-aortic balloon pump (14.8%) and TandemHeart (LivaNova Inc.) (10.0%). Prophylactic MCS patients were more likely to have diabetes mellitus (55% vs 42%, p <0.001) and had more complex lesions compared with cases without prophylactic MCS (Japan-CTO score: 2.80 ± 1.22 vs 2.39 ± 1.27, p <0.001). Cases with prophylactic MCS had similar technical (86% vs 87%, p = 0.643) but lower procedural (80% vs 86%, p = 0.028) success rates and higher rates of periprocedural major cardiac adverse events compared with no prophylactic MCS use (6.55% vs 1.68%, p <0.001). Urgent MCS use was associated with lower technical (68% vs 87%, p <0.001) and procedural (39% vs 86%, p <0.001) success rates and higher major cardiac adverse events compared with no-MCS use (32.26% vs 1.68%, p <0.001). The differences persisted in multivariable analyses. In summary, in this contemporary multicenter registry, MCS was used in 4.5% of CTO PCIs, mostly prophylactically (78.7%). Elective MCS cases had similar technical success but a higher risk of complications. Urgent MCS cases had lower technical and procedural success and higher periprocedural major complication rates.

Myocardial viability mapping by magnetic resonance-based multiparametric systolic strain analysis.

BACKGROUND: Regional myocardial contractility can be characterized by three-dimensional left ventricular (LV) multiparametric strain maps generated from sequential magnetic resonance imaging of radiofrequency tissue-tagging grid point displacements. METHODS: Normal average and standard deviation values for each of three strain indices at 15,300 LV points were determined from a normal volunteer human strain database (n = 50) by application of magnetic resonance-based three-dimensional strain analysis. Patient-specific multiparametric strain data from each ischemic cardiomyopathy patient (n = 20) were then submitted to a point-by-point comparison (n = 15,300 LV points) to the normal strain database. The resulting 15,300 composite multiparametric Z-score values (standard deviation from normal average) were color-contour mapped over patient-specific three-dimensional LV geometry to detect the abnormal contractile patterns associated with myocardial infarction and nonviable myocardium. RESULTS: The average multiparametric strain composite Z-score from each LV region (n = 120) was compared with the respective clinical standard viability testing result and used to construct a receiver-operator characteristic curve. The area under the curve was 0.941 (p < 0.001; 95% confidence interval: 0.897 to 0.985). A regional average Z-score threshold of 1.525 (> 1.525 being nonviable) resulted in a sensitivity of 90% and a specificity of 90%. Corresponding positive and negative predictive values were 84% and 95%, respectively. CONCLUSIONS: The clinical application of magnetic resonance-based multiparametric strain analysis allowed accurate regional characterization and visualization of LV myocardial viability.

From randomized trials to routine clinical practice: an evidence-based approach for the use of drug-eluting stents.

The availability of drug-eluting stents has resulted in a paradigm shift in the management of patients with coronary artery disease with a substantial increase in the percentage of patients being revascularized percutaneously rather than surgically. Since its introduction, there has been a tremendous increase in the use of drug-eluting stents with nearly 90% of patients in the US who undergo percutaneous interventions receiving drug-eluting stents. The promising results of several randomized trials that demonstrated a profound reduction in restenosis rates compared with bare-metal stents, underscores the unprecedented enthusiasm among the cardiology community to adopt this new technology swiftly. Data regarding the safety and superiority of drug-eluting stents abound, and it is imperative for the practicing clinician to review and apply them in appropriate clinical settings. In this review, we present general concepts of drug-eluting stents, and attempt to summarize the available data on the approved drug-eluting stents in a variety of patient and lesion subsets. In addition, we share some insights regarding the potential limitations, and issues specific to drug-eluting stents.

Left ventricular wall stress in patients with severe aortic insufficiency with finite element analysis.

BACKGROUND: Severe aortic insufficiency (AI) with preserved left ventricular (LV) function may be associated with a long asymptomatic period and unpredictable course on medical therapy. Since myocardial wall stress is closely related to both pathologic cardiac remodeling and ultimately to LV decompensation, a more accurate description of regional wall stress may improve our ability to appropriately manage these patients. The objective of this study was to define differences in instantaneous global and regional three-dimensional end-systolic maximum principal stress (ESS) between normal patients and patients with AI, both before and after aortic valve replacement (AVR) using magnetic resonance imaging (MRI) and finite element analysis (FEA). METHODS: Magnetic resonance imaging was performed on 20 normal volunteers and 14 patients with moderate to severe AI with normal systolic function (ejection fraction: 57 +/- 0.6) before and after AVR. Finite element analysis was utilized to estimate global and regional ESS. RESULTS: Both global (p < 0.001) and regional (p < 0.001 in all segments) ESS were significantly higher in the preoperative AI patients when compared with their postoperative values and normal controls. Postoperative ESS was significantly lower than the normal controls (p = 0.002). CONCLUSIONS: Three-dimensional regional and global end-systolic LV wall stress can be determined by MRI and finite element analysis. Values of ESS in patients with chronic AI were elevated prior to AVR and normalized after AVR. This method may have considerable potential as a noninvasive, clinically applicable index of regional LV geometry and function that may help with the serial evaluation of patients with AI.

Low-dose dobutamine tissue-tagged magnetic resonance imaging with 3-dimensional strain analysis allows assessment of myocardial viability in patients with ischemic cardiomyopathy.

BACKGROUND: Tissue-tagged magnetic resonance imaging (MRI) with 3-dimensional (3D) myocardial strain analysis allows quantitative assessment of myocardial contractility. We assessed the hypothesis that 3D strain determination at rest and with low-dose dobutamine would discriminate between viable and nonviable myocardium in patients with ischemic cardiomyopathy (ICM). METHODS AND RESULTS: MRI with radiofrequency tissue-tagging at rest and with low-dose dobutamine was performed in 16 normal volunteers and 14 patients with ICM. Three-dimensional global and regional circumferential strains (Ecc) were computed for all subjects at rest and with dobutamine. Results were compared with clinically indicated conventional viability studies. Compared with normal volunteers, global left ventricular Ecc was significantly decreased in patients with ICM at rest (-0.15+/-0.06 versus -0.27+/-0.03; P<0.001) and with dobutamine (-0.17+/-0.08 versus -0.37+/-0.10; P<0.001). Ecc was significantly decreased in nonviable regions compared with viable segments at rest (-0.08+/-0.06 versus -0.17+/-0.10; P<0.001) and with dobutamine (-0.07+/-0.06 versus -0.21+/-0.11; P<0.001). Ecc in viable segments increased significantly in response to dobutamine (P=0.04), whereas Ecc did not change in nonviable segments (P=0.50). Normal controls (96 segments) had increased Ecc at rest (-0.27+/-0.07) and with dobutamine (-0.37+/-0.15) compared with both viable and nonviable regions in ICM patients (P<0.001). CONCLUSIONS: Noninvasive dobutamine tissue-tagged MRI with calculation of 3D strain allows the identification, quantification and display of regionally varying ventricular function. The response of systolic strain to low-dose dobutamine has significant promise in discriminating between viable and nonviable myocardium.

Myocardial systolic strain is decreased after aortic valve replacement in patients with aortic insufficiency.

BACKGROUND: Left ventricular three-dimensional nonlinear systolic strain determinations have potential to detect small decrements in ventricular function in patients with aortic insufficiency before and after aortic valve replacement. METHODS: Magnetic resonance imaging with tissue-tagging was performed on 42 normal volunteers and 14 patients with chronic aortic insufficiency both before and 28 +/- 11 months after aortic valve replacement. Preoperative and postoperative left ventricular volume, dimensions and ejection fraction were determined for all subjects. Left ventricular systolic radial, circumferential, longitudinal, and minimum principal strain were calculated for six left ventricular regions. RESULTS: After aortic valve replacement, left ventricular volume and dimensions decreased significantly (p < 0.001) and ejection fraction increased nonsignificantly (p = 0.096). Strain values in preoperative aortic insufficiency patients did not differ significantly from controls. At an average of 28 +/- 11 months postoperatively, however, regional three-dimensional minimum principal and longitudinal strain was decreased in all six ventricular regions as well as globally (p < 0.03) compared with normal control values. Circumferential strain was significantly decreased globally and in all but two regions (p < 0.03). CONCLUSIONS: These magnetic resonance imaging-based techniques are sensitive enough to detect a previously unrecognized, significant decrease in both global and regional three-dimensional left ventricular systolic strain 2 years after aortic valve replacement for minimally symptomatic chronic aortic insufficiency despite improvement in ejection fraction and a decrease in left ventricular size. The reasons for a significant decline in left ventricular systolic strain after successful aortic valve replacement in minimally symptomatic chronic aortic insufficiency patients are not clear and warrant further investigation.

Aortic valve replacement for aortic insufficiency: valve type as a determinant of systolic strain recovery.

BACKGROUND AND AIM: Left ventricular (LV) 3D systolic strain decreases in absolute value postoperatively and does not recover in patients who undergo aortic valve replacement (AVR) for chronic aortic insufficiency (AI). We investigated whether choice of valve prosthesis (mechanical [St. Jude], bioprosthetic [bovine pericardial], Ross procedure) had a significant impact on strain recovery in this surgical population. METHODS: MRI with tissue-tagging was performed on 14 patients with chronic AI both before and 28 +/- 13 months after AVR. Average values of LV systolic strain and end-systolic stress (ESS) were computed from MRI data for the LV. Three types of prosthetic valve were examined (Ross procedure n = 4, bovine pericardial n = 5, and St. Jude n = 5). RESULTS: Overall, systolic strain, ESS, LV volumes, ejection fraction, and LV mass all changed significantly following AVR. Comparisons between individual valve types revealed no differences in any of these measurements. Patients who received a mechanical valve had a greater decrease in the absolute value of systolic strain following surgery compared to patients from the nonmechanical group (Ross procedure and bioprosthetic valve). Comparisons between the Ross group and the prosthetic group (St. Jude and bioprosthetic) produced no significant differences in strain, ESS, LV volume, and mass. CONCLUSIONS: These early results suggest that valve prosthetic type may be a factor in efforts to improve strain recovery after AVR for AI, although further investigation is warranted. MRI with tissue-tagging may be a useful tool for comparing the impact of prosthetic valve choice on incompletely recovered systolic strain following AVR for chronic AI.