Angiography-derived physiological assessment after percutaneous coronary intervention of chronic total occlusions.

Scant data exploring potential suboptimal physiological results after angiographic successful percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) are available. Sixty cases of successful CTO-PCI were selected for this retrospective analysis. Post-CTO-PCI angiography-based fractional flow reserve was computed using the Murray-based fractional flow reserve (µFR) software. Vessel-specific µFR, residual trans-stent gradient (TSG) and corrected TSGstent were calculated. In physiological suboptimal results (µFR < 0.90), the virtual pullback pressure gradient (PPG) curves were analyzed to localize the main pressure drop-down and characterize the patterns of residual disease. The virtual pullback pressure gradient index (vPPGi) was then calculated to objectively characterize the predominant pattern of residual disease (diffuse vs focal). The physiological result was suboptimal in 28 cases (46.7%). The main pressure drop was localised proximal to the stent in 2 (7.1%), distal in 17 (60.7%) and intra-stent in 9 cases (32.2%). Intra-stent residual disease was diffuse in 7 cases and mixed in 2. Distal residual disease was characterised by a pure focal pattern in 12 cases, diffuse in 2 and mixed in 3. In the predominant diffuse phenotype (vPPGi < 0.65), we found a higher rate of TSG ≥ 0.04 (61.5% vs 20.0%, p = 0.025) and TSGstent ≥ 0.009 (46.2% vs 20.0%, p = 0.017) while in the dominant focal phenotype poor-quality distal vessel was constantly present. In our cohort, post-CTO-PCI suboptimal physiological result was frequent (46.7%). Predominant focal phenotype was constantly associated with poor-quality distal vessel, while in the predominant diffuse phenotype, the rate of TSG ≥ 0.04 and TSGstent ≥ 0.009 were significantly higher.

Evaluation of Chronic Total Occlusion Recanalization: A Physiologic Assessment Perspective by Dynamic Exercise Tests.

Chronic total occlusion (CTO) recanalization and its effects on left ventricular function and patient outcomes has intrigued the interventional community over the last several years. Now that there is plenty of knowledge and experience on "how to treat" the lesion, another scientific effort should focus on "when to treat" the lesion. Physiologic assessment has altered the way we treat coronary artery stenosis to improve cardiovascular outcomes. We tend to assess the effects of CTO recanalization by evaluating resting parameters, although the effects of ischemia and concomitant left ventricular dysfunction manifest mainly during exercise. Physiologic assessment in CTOs by implementation of cardiopulmonary exercise testing, in order to indirectly assess the physiological effect of exercise-induced left ventricular dysfunction, could represent a novel approach to monitor the effects of CTO recanalization and hopefully to identify the responders after recanalization.

Improvement of left ventricular function assessment by global longitudinal strain after successful percutaneous coronary intervention for chronic total occlusion.

The benefit of revascularization of chronic total occlusion (CTO) in percutaneous coronary intervention (PCI) is controversial. On the other hand, left ventricular (LV) global longitudinal strain (GLS) is a more sensitive marker of LV myocardial ischemia and LV function than LV ejection fraction (EF). The purpose of this study was to investigate the impact of revascularization of CTO on LV function using LV GLS. A total of 70 consecutive patients (65.1±8.9 years, 59 males, LVEF 51.0±12.0%) with CTO who had a positive functional ischemia and underwent PCI, were included in this study. Echocardiography was performed before and 9 months after the procedure with conventional assessment including LV end-diastolic and end-systolic volume (LVEDV, LVESV), LVEF, and with 2DSTE analysis of GLS. Successful PCI was obtained in 60 patients (86%). There were no stent thromboses during follow-up. GLS showed a significant improvement 9 months after successful PCI (pre-PCI -12.4±4.1% vs. post-PCI -14.5±4.1%, P< 0.01), whereas in failed PCI group that did not change significantly (pre-PCI -13.2±4.2% vs. post-PCI -14.0±4.7%, P = 0.64). LVEF, LVEDV and LVESV did not change significantly during follow-up in both successful and failed groups. Successful PCI for CTO improved LV function, assessed by LV GLS.

Assessment of reattempted percutaneous coronary intervention strategy for chronic total occlusion after prior failed procedures: Analysis of the Japanese CTO-PCI Expert Registry.

OBJECTIVES: We aimed to investigate strategies for reattempted percutaneous coronary interventions (PCIs) for chronic total occlusions (CTOs) by highly skilled operators after a failed attempt. BACKGROUND: Development of complex techniques and algorithms has been standardized for CTO-PCI. However, there is no appropriate strategy for CTO-PCI after a failed procedure. METHOD: From 2014 to 2016, the Japanese CTO-PCI Expert Registry included 4,053 consecutive CTO-PCIs (mean age: 66.8 ± 10.9 years; male: 85.6%; Japanese CTO [J-CTO] score: 1.92 ± 1.15). Initial outcomes and strategies for reattempted CTO-PCIs were evaluated and compared with first-attempt CTO-PCIs. RESULTS: Reattempt CTO-PCIs were performed in 820 (20.2%) lesions. The mean J-CTO score of reattempt CTO-PCIs was higher than that of first-attempt CTO-PCIs (2.86 ± 1.03 vs. 1.68 ± 1.05, p < .001). The technical success rate of reattempt CTO-PCIs was lower than that of first-attempt CTO-PCIs (86.7% vs. 90.8%, p < .001). Regarding successful CTO-PCIs, the strategies comprised antegrade alone (reattempt: 36.1%, first attempt: 63.8%), bidirectional approach (reattempt: 54.4%, first attempt: 30.3%), and antegrade approach following a failed bidirectional approach (reattempt: 9.4%, first attempt: 5.4%). Parallel wire technique, intravascular ultrasound guide crossing, and bidirectional approach technique were frequently performed in reattempt CTO-PCIs. Reattempt CTO-PCIs showed higher rates of myocardial infarction (2.1% vs. 0.9%, p < .001) and coronary perforation (6.9% vs. 4.2%, p = .002) than first-attempt CTO-PCIs. CONCLUSIONS: The technical success rate of reattempt CTO-PCIs is lower than that of first-attempt CTO-PCIs. However, using more complex strategies, the success rate of reattempt CTO-PCI can be improved by highly skilled operators.

Assessment of Left Atrial Work During Acute Coronary Occlusion.

Left atrial (LA) work can be measured through speckle tracking echocardiography by calculating LA pressure-strain loop area, which includes two distinct phases of active contraction/relaxation (A-work) and passive dilation/emptying (V-work). Echocardiographic and hemodynamic data were acquired at baseline and during occlusions of left anterior descending (LAD: n = 7) and left circumflex (LCx: n = 9) coronary arteries in dogs. Left ventricular (LV) circumferential strain was decreased and mean LA pressure was increased in both occlusions. Doppler-derived stroke volume was maintained during LAD occlusion, but it decreased during LCx occlusion. A-work increased during LAD occlusion, but it did not change during LCx occlusion. V-work decreased during LCx occlusion more than during LAD occlusion. The compensatory mechanism of LA function was limited during LCx occlusion, but this occurred during LAD occlusion. This study provided insight into a role of LA function in variable hemodynamic consequences in acute myocardial infarction.

A sex stratified outcome analysis from the OPEN-CTO registry.

INTRODUCTION: Women have been under-represented in trials. Due to the dearth of information about CTO-PCI in women and discordance of previous results, sex differences in outcomes in the OPEN-CTO Trial were investigated. METHODS: OPEN-CTO is an investigator-initiated, multicenter, prospective observational registry of consecutive CTO patients undergoing PCI at 12 U.S. centers. The one-year outcomes of this trial stratified by sex were examined. Optimal propensity matching was performed to compare outcomes between sexes. Multivariate conditional logistic regression modeling for predictors of procedural success was performed. RESULTS: Women represented 19.6% of the cohort (196/1,000 patients). Women were more likely to report dyspnea as their predominant symptom. Women reported statistically worse physical limitation and poorer quality of life as compared to men. J-CTO scores were similar in males and females. Technical, procedural success and MACE rates were similar in both sexes. Contrast and radiation doses were however significantly lower in women. The SAQ- summary score, RDS, EQ-5D VAS, PHQ-8 scores were all improved to the same degree at 1 year in women as compared to men. Predictors of procedural success revealed that younger age, lower J-CTO score and absence of prior CABG were predictors of procedural success. Sex did not predict procedural success or 1-year MACE in this regression model. CONCLUSION: This real-world registry revealed that women derive the same benefit from CTO-PCI as men without additional complications and with favorable health status outcomes at 1 year. Consideration of revascularization by PCI in symptomatic women should be considered as part of the treatment when appropriate.

Incremental benefit of three-dimensional transthoracic echocardiography in the assessment of left atrial appendage aneurysm leading to severe extrinsic compression of a coronary artery.

Left atrial appendage aneurysm (LAA AN) is a rare disease entity, which can be congenital or acquired in nature. We report an adult patient with LAA AN presenting with anginal chest pain in whom live/real time three-dimensional transthoracic echocardiography (3DTTE) provided incremental value over the two-dimensional (2D) technique in providing a more comprehensive assessment of the lesion. A literature review of the salient features of LAA AN is also provided in a tabular form.

Randomized Comparison of a CrossBoss First Versus Standard Wire Escalation Strategy for Crossing Coronary Chronic Total Occlusions: The CrossBoss First Trial.

OBJECTIVES: The authors performed a multicenter, randomized-controlled, clinical trial comparing upfront use of the CrossBoss catheter versus antegrade wire escalation for antegrade crossing of coronary chronic total occlusions. BACKGROUND: There is equipoise about the optimal initial strategy for crossing coronary chronic total occlusions. METHODS: The primary endpoints were the time required to cross the chronic total occlusion or abort the procedure and the frequency of procedural major adverse cardiovascular events. The secondary endpoints were technical and procedural success, total procedure time, fluoroscopy time required to cross and total fluoroscopy time, total air kerma radiation dose, total contrast volume, and equipment use. RESULTS: Between 2015 and 2017, 246 patients were randomized to the CrossBoss catheter (n = 122) or wire escalation (n = 124) at 11 U.S. centers. The baseline clinical and angiographic characteristics of the study groups were similar. Technical and procedural success were 87.8% and 84.1%, respectively, and were similar in the 2 groups. Crossing time was similar: 56 min (interquartile range: 33 to 93 min) in the CrossBoss group and 66 min (interquartile range: 36 to 105 min) in the wire escalation group (p = 0.323), as was as the incidence of procedural major adverse cardiovascular events (3.28% vs. 4.03%; p = 1.000). There were no significant differences in the secondary study endpoints. CONCLUSIONS: As compared with wire escalation, upfront use of the CrossBoss catheter for antegrade crossing of coronary chronic total occlusions was associated with similar crossing time, similar success and complication rates, and similar equipment use and cost.

Association of Stress Test Risk Classification With Health Status After Chronic Total Occlusion Angioplasty (from the Outcomes, Patient Health Status and Efficiency in Chronic Total Occlusion Hybrid Procedures [OPEN-CTO] Study).

Stress testing is endorsed by the American College of Cardiology/American Heart Association Appropriate Use Criteria to identify appropriate candidates for Chronic Total Occlusion (CTO) Percutaneous Coronary Intervention (PCI). However, the relation between stress test risk classification and health status after CTO PCI is not known. We studied 449 patients in the 12-center OPEN CTO registry who underwent stress testing before successful CTO PCI, comparing outcomes of patients with low-risk (LR) versus intermediate to high-risk (IHR) findings. Health status was assessed using the Seattle Angina Questionnaire Angina Frequency (SAQ AF), Quality of Life (SAQ QoL), and Summary Scores (SAQ SS). Stress tests were LR in 40 (8.9%) and IHR in 409 (91.1%) patients. There were greater improvements on the SAQ AF (LR vs IHR 14.2 ± 2.7 vs 23.3 ± 1.3 points, p <0.001) and SAQ SS (LR vs IHR 20.8 ± 2.3 vs 25.4 ± 1.1 points, p = 0.03) in patients with IHR findings, but there was no difference between groups on the SAQ QoL domain (LR vs IHR 24.8 ± 3.4 vs 27.3 ± 1.6 points, p = 0.42). We observed large health status improvements after CTO PCI in both the LR and IHR groups, with the greatest reduction in angina among those with IHR stress tests. Although patients with higher risk studies may experience greater reduction in angina symptoms, on average, patients with LR stress tests also experienced large improvements in symptoms after CTO PCI, suggesting patients with refractory symptoms should be considered appropriate candidates for CTO PCI regardless of stress test findings.

Safety and efficacy of intracoronary sodium nitroprusside for the assessment of coronary fractional flow reserve.

BACKGROUND: Coronary fractional flow reserve (FFR) determination is a valuable tool for the assessment of stenosis significance in intermediate coronary obstructions. Maximal hyperemia is mandatory for this determination. Although intravenous (IV) Adenosine is the standard agent used, its use carries an elevated incidence of side effects. Intracoronary sodium nitroprusside (IC NTP) is a very well-known coronary vasodilator, but it is not routinely used for FFR determinations. OBJECTIVES: The purpose of the present study was to compare FFR determinations and side effect profile of IC NTP with IV Adenosine. METHODS: We prospectively assessed FFR determinations in a total of 20 intermediate coronary artery stenotic lesions in 18 consecutive patients with the administration of IV Adenosine (140 µg/kg/min) and IC NTP (100 µg). The appearance of side effects was registered. RESULTS: The mean age was 55.5 ±â€¯7.5 years. Fifteen (83%) of the patients were male. Mean FFR values with IC NTP were similar to those obtained with IV Adenosine (0.82 ±â€¯0.07 vs 0.82 ±â€¯0.06, respectively, r = 0.775, p < 0.0001). Intravenous Adenosine induced side effects in 45% of patients (shortness of breath 30%, flushing 5%, headache 5%, angina pectoris 5%, and transient conduction disturbances 10%). No side effects were reported with IC NTP. CONCLUSIONS: IC NTP at a dose of 100 µg is as effective as IV Adenosine for FFR assessment. Besides, it is better tolerated and should be consider as a vasodilator agent in the assessment of FFR.

Left ventricular longitudinal function assessment in rabbits after acute occlusion of left anterior descending coronary artery by two-dimensional speckle tracking imaging.

ABSTACT: BACKGROUND: To evaluate the left ventricular (LV) longitudinal function changes in rabbits after acute occlusion of the left anterior descending artery (LAD) by two-dimensional speckle tracking imaging (2D-STI). METHODS: Forty-eight New Zealand white rabbits underwent echocardiography examination. EchoPAC was used to measure LV peak systolic longitudinal strain (LS) of the endocardium, middle myocardium, and epicardium, peak longitudinal strain rate (LSr), segmental and global longitudinal rotation (LR) degrees. Ligated the LAD and repeated all measurements after 10 min. RESULTS: Peak LS and LSr were significantly different between the preoperative and postoperative rabbits among most LV walls (P < 0.05). In apical four-chamber view, there was significant difference in the degrees of rotation of the LV lateral wall in preoperative and postoperative rabbits (P < 0.05). In apical three-chamber view, the rotation degrees of the posterior wall and the LR were significantly lower in the postoperative than in the preoperative (P < 0.001). In apical two-chamber view, the rotation degrees of the inferior wall and the LR were significantly lower in the postoperative (P < 0.05). CONCLUSIONS: Left ventricular function was impaired after acute occlusion of LAD. Segmental rotational degrees and changes in LR could be useful indicators of cardiac function during the early phases of acute myocardial ischemia.

The effectiveness of super-selective injection with anchor balloon technique for collateral channel assessment.

The careful assessment of collateral channels is important for a retrograde approach for a chronic total coronary occlusion (CTO). This case report describes a percutaneous coronary intervention for CTO of the distal right coronary artery with good collateral circulation. All visible collateral channels failed by the retrograde approach; however, the procedure was successful using the distal atrial circumflex (AC) channel. Although this distal channel was poorly visualized on standard coronary angiography, it was clearly contrasted retrogradely from the CTO exit using a super-selective injection through the proximal AC channel as the antegrade flow was obstructed by the anchor balloon. This case highlights a unique super-selective injection with anchor balloon technique for collateral channel assessment.

Epidemiology, Management Strategies, and Outcomes of Patients With Chronic Total Coronary Occlusion.

Factors influencing the management of patients with chronic total occlusion (CTO) are poorly described. We sought to analyze the clinical and angiographic variables influencing the decision-making process of patients with CTO. Consecutive patients with at least 1 coronary artery CTO were included and categorized as managed either by percutaneous coronary intervention (PCI), coronary artery bypass graft (CABG), or medical therapy (MT). Patients with previous CABG were excluded. The CTO SYNTAX score (CTO-SS) was defined as the ratio between the score attributed to the CTO lesion in the SYNTAX score calculation and the total SYNTAX score. Independent predictors of management strategies were sought. A total of 510 patients were included (CTO incidence: 20%): 9% were treated with PCI, 34% with CABG, and 57% with MT. SYNTAX score was lowest in PCI (14.8 [11.0 to 18.5]) and highest in CABG (31.5 [25.0 to 38.8], p <0.0001). PCI was attempted more often in patients with higher CTO-SS (i.e., those with higher contribution to the overall SYNTAX score from the CTO lesion; 88% had a CTO-SS >0.5). Conversely, CABG was preferred in subjects with lower CTO-SS (61% had a CTO-SS ≤0.5, p <0.0001). Age, ejection fraction, SYNTAX score, and age of the CTO were independent predictors of revascularization. At mid-term follow-up, unsuccessful revascularization or MT was independently associated with death (hazard ratio 7.2, p = 0.0005). In conclusion, CTOs are frequently documented in clinical practice. However, less than a half is revascularized. Management strategies are influenced by angiographic variables such as the SYNTAX score and the newly proposed CTO-SS.

Echocardiographic assessment of right ventricular functions in patients with proximal right coronary artery chronic total occlusion.

To assess right ventricular functions by echocardiography in patients with proximal right coronary artery (RCA) CTO and correlating it with clinical and angiographic variables. We studied 60 consecutive patients with CTO of the proximal RCA and no other significant lesions in the left coronary system. Echocardiography was performed in order to measure left ventricular (LV) dimensions, LVEF, RV end diastolic area (RVEDA), RV end systolic area (RVESA), RV fractional area change (RVFAC), tricuspid annular plane systolic excursion (TAPSE), Doppler myocardial performance index (MPI), trans-tricuspid E and A waves, E/A ratio, S', e' and a'. Grades of coronary collaterals was assessed. Doppler MPI showed negative correlation with TAPSE (r = -0.8997, p < 0.0001) and RVFAC (r = -0.928, p < 0.0001). Positive correlation with trans-tricuspid E/A ratio (r = 0.893, p < 0.0001) and E/e' ratio (r = 0.783, p < 0.0001). Patients with no evidence of MI had more well-developed (grade 3) coronary collaterals (83.8 vs. 17.4 %). Patients with evidence of MI had lower RVFAC 38.13 ± 5.39 versus 45.08 ± 4.99 % (p < 0.0001), lower TAPSE 20.17 ± 3.85 versus 25.35 ± 3.46 mm (p < 0.0001), higher MPI 0.4 ± 0.08 versus 0.31 ± 0.05 (p < 0.0001), higher trans-tricuspid E/A ratio 1.79 ± 0.38 versus 1.13 ± 0.36 (p < 0.0001) and E/e' ratio 5.23 ± 1.02 versus 3.61 ± 0.88 (p < 0.0001). Patients with poorly developed collaterals had lower TAPSE and RVFAC and a higher MPI (p < 0.0001 for each). Patients with proximal RCA CTOs and evidence of inferior wall MI have significant impairment of RV functions in addition to poorly developed coronary collaterals. Those with proximal RCA CTOs and well-developed coronary collaterals have better RV functions.

Assessment of Inducible Myocardial Ischemia, Quality of Life, and Functional Status After Successful Percutaneous Revascularization in Patients With Chronic Total Coronary Occlusion.

The benefits of chronic total coronary occlusion (CTO) revascularization are not well established. In this prospective cohort study, 47 consecutive patients with successful percutaneous recanalization of CTO underwent adenosine stress cardiac magnetic resonance (CMR), 6-minute walk test (6MWT), and the Short Form-36 Health Survey before and 6 months after the procedure. Successful recanalization of a CTO was followed by significant improvement of (1) global physical and mental health status; (2) the distance walked in the 6MWT; (3) the incidence of chest pain at the end of the 6MWT; and (4) the score of a novel CMR ischemic burden index on the basis of the characteristics of adenosine stress perfusion defects (extension, persistence, transmurality, and induced contractile regional dysfunction). Patients with greater CMR ischemic index before percutaneous revascularization showed better improvement in the 6MWT. In conclusion, successful recanalization of a CTO leads to a concurrent improvement in ischemic burden, exercise tolerance, angina frequency, and quality of life scores. Patients with a high ischemic CMR score before CTO recanalization showed the better improvement in exercise tolerance.

Echocardiographic assessment of global longitudinal right ventricular function in patients with an acute inferior ST elevation myocardial infarction and proximal right coronary artery occlusion.

Right ventricular (RV) myocardial infarction (MI) is a frequent concomitant of an acute inferior MI. We set out to determine the diagnostic value of speckle tracking echocardiography in comparison with cardiac magnetic resonance (CMR) for RV stunning and scar prediction. 55 patients (66 ± 11 years) with an acute inferior ST elevation MI who underwent percutaneous coronary intervention (PCI) of an occlusion in the proximal right coronary artery were prospectively enrolled. An echocardiography was done on the day of presentation and on the 5th day thereafter. A CMR was subsequently performed 1 month after the MI. The CMR was used to differentiate between the group with RV scar (n = 26) and without RV scar (n = 29). RV peak systolic longitudinal strain (RV-LS) at presentation determined RV scar (-21.1 ± 5.1% vs. -9.9 ± 4.6%, p < 0.0001). The RV-LS correlated with the scar extent (r = 0.83, p < 0.0001). RV-LS > -15.8% had a sensitivity of 92% and a specificity of 83% in RV scar prediction (AUC 0.93). RV-LS was superior to TAPSE and TDI in determining the presence of RV scar. According to RV-LS values at presentation and on the 5th day, 3 subgroups were defined: G1-normal deformation (RV-LS <-20%), G2-RV stunning (baseline RV-LS >-20%, 5th day RV-LS <-20%) and G3-persistent RV dysfunction (unchanged RV-LS > -20%). In G1, there was neither RV scar nor clinically relevant hypotension. In G2, 58% of patients developed RV scar and 36% had hypotension. In the G3, 83% developed RV scar and 55% had hypotension. The myocardial deformation analysis could provide an early prediction of RV scar. It allowed the patients to be divided into subgroups with normal RV function, stunning and persistent RV dysfunction.

Impact of microvascular obstruction on the assessment of coronary flow reserve, index of microcirculatory resistance, and fractional flow reserve after ST-segment elevation myocardial infarction.

BACKGROUND: Invasive assessment of coronary physiology (IACP) offers important prognostic insights in ST-segment elevation myocardial infarction (STEMI) but the dynamics of coronary recovery are poorly understood. OBJECTIVES: This study sought to examine the evolution of coronary flow reserve (CFR), index of microcirculatory resistance (IMR), ratio of distal coronary pressure (Pd) to mean aortic pressure (Pa), and fractional flow reserve (FFR) in patients undergoing primary percutaneous coronary intervention (PPCI). METHODS: 82 patients with STEMI underwent IACP at PPCI. Repeat IACP was performed in 61 patients (74%) at day 1 and in 46 patients (56%) at 6 months. Contrast-enhanced cardiac magnetic resonance imaging (CMR) was performed in 45 patients (55%) at day 1 and in 41 patients (50%) at 6 months. Changes in IACP were compared between patients with and without microvascular obstruction (MVO) on CMR. RESULTS: MVO was present in 21 of 45 patients (47%). Patients with MVO had lower CFR at PPCI and day 1 (p < 0.05) and a trend toward higher IMR values (p = 0.07). At 6 months, CFR and IMR were not significantly different between the groups. Baseline flow and Pd/Pa remained stable over time but FFR reduced significantly between PPCI and 6 months (p = 0.008); this reduction was mainly observed in patients with MVO (p = 0.006) but not in those without MVO (p = 0.21). CONCLUSIONS: In PPCI-treated patients with STEMI, coronary microcirculation begins to recover within 24 h and recovery progresses further by 6 months. FFR significantly reduces from baseline to 6 months. The presence of MVO indicates a highly dysfunctional microcirculation.