Contemporary balloon aortic valvuloplasty: Changing indications and refined technique.

Even if un to improve long-term prognosis, balloon aortic valvuloplasty (BAV) may be useful in selected patients with symptomatic severe aortic stenosis either as a bridge to surgical or transcatheter valve replacement (aortic valve replacement [AVR] or transcatheter aortic valve implantation [TAVI]) or as a triage strategy for patients with uncertain indications. International guidelines recommend BAV as: a "bridge" to AVR/TAVI, a "trial" in patients with undetermined symptoms, or a "bridge-to-decision" in case of comorbidities. However, in clinical practice, BAV is also used as a palliative measure to improve hemodynamics and quality of life in many patients who are excluded from AVR/TAVI. Finally, BAV is often performed during TAVI to facilitate prosthesis delivery, optimize frame expansion, or for bioprosthetic valve fracture in selected valve-in-valve procedures. Technical innovations, which allow for a mini-invasive approach via transradial access and pacing delivered through the wire, have led to a decrease in complications over time. This review focuses on contemporary BAV with a specific emphasis on new indications, innovative techniques, and specific complex patient subgroups.

Vascular complications after balloon aortic valvuloplasty in recent years: Incidence and comparison of two hemostatic devices.

OBJECTIVES: To define the incidence of vascular complications (VC) after balloon aortic valvuloplasty (BAV) in recent years, and to compare the performance of two vascular closure devices (VCD). BACKGROUND: VC remain the most frequent drawback of BAV and are associated with adverse clinical outcomes. METHODS: All BAV procedures performed at 2 high-volume centers over a 6-year period (n = 930) were collected in prospective registries and investigated to assess the incidence of Valve Academic Research Consortium-2 (VARC-2) defined VC. Incidence of life-threatening, major and minor bleeding was also assessed. In-hospital major adverse cardiac and cerebrovascular events (MACCE) rate (composite of in-hospital death, myocardial infarction, TIA/stroke, and life-threatening bleeding) as well as 30-day survival was compared between a suture-mediated closure system and a collagen plug hemostatic device. RESULTS: A 9 Fr arterial sheath was used in most of the patients (84.1%). Vascular closure was obtained with the Angio-Seal in 643 patients (69.1%) and the ProGlide in 287 (30.9%). The overall incidence of major VC was 2.7%, and minor VC 6.6%, without significant differences between groups. The Angio-Seal group was associated with a higher rate of small hematomas (6.9% vs. 3.5%, P = 0.042), whilst blood transfusions were more frequent in the ProGlide group (6.6% vs. 3.5%, P = 0.034). Rates of in-hospital MACCE and 30-day survival were similar. Use of either VCD was not independently associated with major VC. CONCLUSIONS: VC rate after BAV is fairly low in experienced centers without major differences between the 2 most used VCD.

Randomized comparison of balloon aortic valvuloplasty performed with or without rapid cardiac pacing: The pacing versus no pacing (PNP) study.

OBJECTIVES: To compare the effectiveness and safety of balloon aortic valvuloplasty (BAV) performed with or without rapid ventricular pacing (RP). BACKGROUND: BAV technique is poorly standardized. METHODS: One hundred consecutive patients were randomly assigned 1:1 between BAV performed with or without RP. Exclusion criteria were an immediate indication for surgical or transcatheter aortic valve replacement, presentation in cardiogenic shock or pulmonary edema refractory to medical stabilization. RESULTS: There were 51 patients in the BAV group performed with RP, 49 in the BAV group without RP (noRP). Procedural success (50% hemodynamic gradient reduction) was achieved in 37.3% and 55.1%, respectively (P = 0.16). Fewer people in the noRP group complained of poor tolerance to the procedure (16% vs 41%). The primary efficacy endpoint, a 50% reduction in the mean echocardiographic trans-aortic gradient, was met in 21/49 patients in the noRP group compared to 20/51 in the RP (42.9% vs 39.2%; P = 0.84). No significant difference between the groups was observed in the primary safety endpoint, a 30-day composite of death, myocardial infarction, stroke, acute aortic regurgitation, and BARC bleeding ≥3 (8.2% noRP vs 13.7%; P = 0.53). The noRP group required fewer bailout temporary pacemakers (P = 0.048) and had a lower incidence of moderate/severe renal function worsening (4.1% vs 17.6%; P = 0.052). CONCLUSIONS: Rapid ventricular pacing did not influence BAV efficacy or safety and tolerance was slightly worse.

Incidence, treatment, and outcome of acute aortic valve regurgitation complicating percutaneous balloon aortic valvuloplasty.

OBJECTIVES: To evaluate the incidence, treatment, and outcomes of acute aortic regurgitation (ARR) complicating BAV. BACKGROUND: In the transcatheter aortic valve implantation (TAVI) era, there is an increase of percutaneous balloon aortic valvuloplasty (BAV) procedures with different indications. METHODS: From the prospective BAV registry of the University of Bologna, which has enrolled patients between the year 2000 and the present, we selected those who suffered intraprocedural AAR with overt hemodynamic instability. Worsening of baseline aortic insufficiency without hemodynamic collapse, treatment of degenerated biological valve prosthesis, and BAV performed within a planned TAVI procedure were excluded. The main endpoints were in-hospital and 30-day mortality. RESULTS: Out of 1517 BAVs, we identified 26 cases of AAR (1.7%). This complication occurred in 80.8% of cases after one or two balloon inflations. Mean transaortic gradient decreased from 50.6 ± 19.3 to 26.0 ± 14.4 mm Hg (p < 0.01). In 8(30.8%) patients, AAR spontaneously resolved within few minutes; in 18 cases, the operators had to perform a rescue maneuver to reposition a valve leaflet got stuck in the opening position (this maneuver was successful in 13/18 of the cases, 72.2%). Out of 5 persistent AAR, 3 were managed with emergency TAVI or surgery, while 2 were unresolved. In-hospital mortality was 15.4% (n = 4), whereas no more deaths occurred up to 30 days. CONCLUSIONS: AAR is a fearsome complication of BAV and portends a grim prognosis. In some cases, it can be resolved with appropriate technical maneuvers; in others, a rescue TAVI or surgical valve replacement may be necessary. © 2015 Wiley Periodicals, Inc.

Inducing Persistent Flow Disturbances Accelerates Atherogenesis and Promotes Thin Cap Fibroatheroma Development in D374Y-PCSK9 Hypercholesterolemic Minipigs.

BACKGROUND: Although disturbed flow is thought to play a central role in the development of advanced coronary atherosclerotic plaques, no causal relationship has been established. We evaluated whether inducing disturbed flow would cause the development of advanced coronary plaques, including thin cap fibroatheroma. METHODS AND RESULTS: D374Y-PCSK9 hypercholesterolemic minipigs (n=5) were instrumented with an intracoronary shear-modifying stent (SMS). Frequency-domain optical coherence tomography was obtained at baseline, immediately poststent, 19 weeks, and 34 weeks, and used to compute shear stress metrics of disturbed flow. At 34 weeks, plaque type was assessed within serially collected histological sections and coregistered to the distribution of each shear metric. The SMS caused a flow-limiting stenosis, and blood flow exiting the SMS caused regions of increased shear stress on the outer curvature and large regions of low and multidirectional shear stress on the inner curvature of the vessel. As a result, plaque burden was ≈3-fold higher downstream of the SMS than both upstream of the SMS and in the control artery (P<0.001). Advanced plaques were also primarily observed downstream of the SMS, in locations initially exposed to both low (P<0.002) and multidirectional (P<0.002) shear stress. Thin cap fibroatheroma regions demonstrated significantly lower shear stress that persisted over the duration of the study in comparison with other plaque types (P<0.005). CONCLUSIONS: These data support a causal role for lowered and multidirectional shear stress in the initiation of advanced coronary atherosclerotic plaques. Persistently lowered shear stress appears to be the principal flow disturbance needed for the formation of thin cap fibroatheroma.

Case Report: Asymptomatic SARS-COV2 infection triggering recurrent Takotsubo syndrome.

Takotsubo syndrome (TTS) is a rare disease mimicking acute coronary syndrome, often triggered by physical or emotional stress, and characterized by transient left ventricular dysfunction. Recurrences are described in about 5% of cases and may have different clinical and imaging patterns. In the present report, SARS-COV-2 infection, even in the absence of symptoms and overt emotional stress, seems correlated with recurrence of TTS, due to the absence of other recognized triggers. The hypothesis is that in predisposed patients, events like catecholamine-induced myocyte injury, direct viral damage, cytokine storm, immune-mediated damage, and procoagulant state, all possibly induced by the infection, may elicit endothelial dysfunction as substrate for TTS onset.

Prolactin Inhibition to Treat Postpartum Arrhythmic Storm.

Postpartum electrical storm due to torsade de pointes is a rare but life-threatening condition. The uniqueness of this case lies in the use of cabergoline to suppress postpartum ventricular arrhythmias in absence of heart disease. Timely multidisciplinary management is crucial to achieve final diagnosis, deliver proper treatment and improve prognosis.

Aortic balloon valvuloplasty outcome according to calcium distribution and valve geometry - The ABCD study.

BACKGROUND: There is little data on the outcome of balloon aortic valvuloplasty (BAV) in relation to valve dimensions and calcification patterns. The procedure is not standardized, particularly the choice of balloon size. METHODS: This retrospective multicenter study focused on BAV efficacy and safety by analyzing the relationship between balloon size, annulus geometry (i.e., diameters, perimeter, and area), and calcification patterns (total burden and calcium distribution over each individual leaflet). From March 2018 to March 2023, all consecutive patients who underwent clinically indicated BAV and ECG-gated multidetector computed tomography of the aorta were included, except those with a bicuspid valve. Calcium score was calculated on contrast-enhanced images based on a luminal attenuation threshold of +100 HU. RESULTS: One hundred and fifteen patients were included. Procedural success was 82.6 %. The balloon-to-annulus ratio (BAR) relative to diameter, perimeter, and area was higher in patients with successful BAV. Patients with unsuccessful BAV had a significantly higher aortic valve calcium burden. The complication rate was 4.3 % and there was no association with valve geometry or calcium burden. A trend towards a reduced complication rate was found as calcium asymmetry increased. BAR minimum annulus diameter was the best parameter in predicting procedural success, with a cut-off at 0.85. CONCLUSIONS: BAV efficacy is correlated directly with balloon size in relation to annulus dimension and inversely with total calcium burden. The minimum diameter of the valve may be adopted as a reference for balloon sizing.

Long-term outcomes of patients treated with sirolimus-eluting resorbable magnesium scaffolds: Insights from the SHERPA-MAGIC study.

BACKGROUND: The resorbable magnesium scaffold (RMS) is a second-generation bioresorbable scaffold (BRS) that has shown conflicting results in previous studies. These findings suggest that patient selection and implantation technique may have an impact on clinical outcomes. This study aimed to investigate the safety and long-term effectiveness of RMS in a narrowly selected population. METHODS: SHERPA-MAGIC is an investigator-driven, multicenter, prospective, single-arm study that enrolled patients undergoing BRS coronary implantation in 18 Italian centers. The present analysis considered the first 543 enrolled patients treated with RMS, with a minimum follow-up of 1 year. The study protocol included strict criteria for patient selection and standardization of RMS implantation. The primary outcome was the occurrence of the vessel-oriented composite endpoints (VOCE), including cardiac death, target vessel myocardial infarction, and ischemia-driven target vessel revascularization. RESULTS: Overall, 635 vessels were treated. The 1-year cumulative occurrence of VOCE was 22 (3.5%, 95% CI 2.2%-5.2%), which was significantly lower than the prespecified estimation (from 5.5% to 8.5%). At the median follow-up of 3.5 [2.6-4.3] years, there were 3 (0.5%) cardiac deaths, 12 (1.9%) target vessel myocardial infarctions, and 33 (5.2%) ischemia-driven target vessel revascularizations. A total of 37 (5.8%, 95%CI 4.1%-7.9%) VOCEs were detected. Scaffold thrombosis occurred in 4 (0.6%, 95%CI 0.1%-1.6%) cases. Patient-level analysis confirmed the findings of the vessel-level analysis. CONCLUSIONS: These results confirm the safety and performance of RMS technology. If confirmed in randomized controlled trials, they may rekindle interest in the use of scaffolds in daily practice.

Is balloon aortic valvuloplasty safe in patients with significant aortic valve regurgitation?

OBJECTIVES: To assess safety and effectiveness of balloon aortic valvuloplasty (BAV) in patients with symptomatic severe aortic stenosis (AS) and significant aortic regurgitation. BACKGROUND: BAV is a palliative procedure that has possibly been underused in patients with symptomatic AS not suitable for surgical aortic valve replacement or transcatheter aortic valve implantation. Significant aortic regurgitation is commonly perceived as a contraindication to BAV. METHODS: Among 416 consecutive patients undergoing BAV at our Institution, 73 patients showed moderate or severe AR before the procedure. Demographics and baseline characteristics, as well as in-hospital clinical outcome, have been prospectively collected in a dedicated database. Transthoracic echocardiography was regularly performed in all patients undergoing BAV before the procedure and at hospital discharge. RESULTS: Patients had a high-risk profile, confirmed by advanced age (77.2 ± 11.8 years) and important comorbidity (logistic Euroscore 26.5 ± 16.3%). Advanced heart failure was present in 73.9%. Indication to BAV was cardiogenic shock in 9.6%, palliation in 31.5%, bridge in 58.9% of the patients. BAV was performed with standard retrograde approach. Aortic valve area increased from 0.62 ± 0.15 cm(2) at baseline to 0.83 ± 0.17 cm(2) before discharge (P < 0.001). The degree of AR was improved or unchanged in 65 patients (89%). In-hospital mortality was 6.9%, mainly limited to terminal patients. Symptomatic status at discharge was improved in all surviving patients. Acute AR occurred in seven patients; in five of them it was successfully resolved in the catheterization laboratory. CONCLUSIONS: When clinically indicated, BAV can be safely performed in patients with combined aortic stenosis and significant aortic regurgitation.

Balloon aortic valvuloplasty: current status and future prospects.

INTRODUCTION: Balloon aortic valvuloplasty (BAV) improves hemodynamic and clinical status of patients with severe aortic stenosis (AS) for a limited period of 6-12 months. However, there is a high number of procedures performed worldwide and an upward trend over the last decades. AREAS COVERED: Epidemiology of AS and the advent of transcatheter aortic valve implantation (TAVI) contribute to the extensive referral of patients. The expansion of recommendations for TAVI has occasionally led to financial reimbursement-related problems that do not exist for BAV. BAV is indicated as a bridge to valve replacement, to decision in complex cases, and to extracardiac surgery. BAV may play a role in preparing for TAVI and optimizing procedural results. The minimalist approach and reduced complication rate make it applicable in fragile patients. EXPERT OPINION: In the near future, BAV will continue to be a useful asset in managing patients with AS given the multiple indications, broad applicability, safety profile, low cost, and repeatability. Specific studies are necessary to explore technical solutions, stronger indications, the finest technique, and to standardize the procedural result. Pending the development of potential competitive devices, the role that BAV plays will remain closely intertwined with the one played by TAVI.

How to deal with vessel diameter mismatch in left main bifurcation stenting.

Left main coronary artery percutaneous coronary intervention is particularly complex when stenting across the distal bifurcation is required in the presence of a diameter mismatch between the proximal main and distal branches. A suboptimal procedural result increases the risk of thrombosis and restenosis. Considering the paucity of data published on this topic, our objective was to provide technical solutions to deal with this complex anatomy. We described four cases showing the use of devices and techniques which allowed us to overcome a diameter discrepancy between adjacent coronary segments: (1) self-expanding nitinol stent; (2) stent platform with noteworthy expansion capacity; (3) the 'extended skirt' technique; (4) the 'trouser-leg' technique. In conclusion, the use of specific strategies and devices allows a safe and effective approach to be used to perform treatment that respects the coronary anatomy, and to optimize percutaneous coronary intervention results in complex scenarios.

Immediate coronary angiography and systematic targeted temperature management are associated with improved outcome in comatose survivors of cardiac arrest.

Rapid and systematic access to coronary angiography (CAG) and target temperature management (TTM) might improve outcome in comatose patients who survive cardiac arrest (CA). However, there is controversy around indicating immediate CAG in the absence of transmural ischemia on the electrocardiogram after return of spontaneous circulation (ROSC). We evaluated the short- and long-term outcome of patients undergoing systematic CAG and TTM, based on whether culprit lesion percutaneous coronary intervention (PCI) was performed. All consecutive comatose CA survivors without obvious extra-cardiac causes undergoing TTM were included. Analysis involved the entire population and subgroups, namely patients with initial unshockable rhythm, no ST elevation on electrocardiogram, and good neurological recovery. We enrolled 107 patients with a median age of 64.9 (57.7-73.6) years. The initial rhythm was shockable in 83 (77.6%). Sixty-six (61.7%) patients underwent PCI. In-hospital survival was 71%. It was 78.8% and 58.5% in those undergoing or not PCI (p = 0.022), respectively. Age, time from CA to ROSC and culprit lesion PCI were independent predictors of in-hospital survival. Long-term survival was significantly higher in patients who underwent PCI (respectively 61.5% vs 34.1%; Log-rank: p = 0.002). Revascularization was associated with better outcomes regardless of initial rhythm (shockable vs non-shockable) and ST deviation (elevation vs no-elevation), and improved the long-term survival of patients discharged with good neurological recovery. Systematic CAG and revascularization, when indicated, were associated with higher survival in comatose patients undergoing TTM, regardless of initial rhythm and ST deviation in the post-ROSC electrocardiogram. The benefit was sustained at long-term particularly in those with neurological recovery.

Effective and equivalent organ doses in patients undergoing coronary angiography and percutaneous coronary intervention.

PURPOSE: Recent recommendations of the International Commission on Radiological Protection state that the use of effective dose (E) for assessing patient exposure has severe limitations, though it can be kept for dose comparisons. In cardiology procedures, the equivalent dose (H(T)) is one of the most appropriate dose quantity to be evaluated for risk-benefit assessment. In this study, both E and H(T) values for ten critical organs in coronary angiography (CA) and percutaneous coronary interventions (PCI) were derived from in-the-field dose-area-product (DAP) measurements in order to provide a database for doses in those procedures. METHODS: Conversion factors E/DAP calculated by Monte Carlo methods in two different mathematical human phantoms were applied to DAP values measured on 193 patients (118 CA and 75 PCI). Partial DAP values were recorded in-the-field for each projection and for all patients. The partial effective doses of all projections were summed up to calculate the E of the entire procedure. Similarly, equivalent doses for ten critical organs/tissues (bone, colon, heart, liver, lung, esophagus, red bone marrow, skin, stomach, and thyroid) were derived from H(T)/DAP conversion factors for different projections calculated by Monte Carlo method. RESULTS: All parameters related to the patient dose, i.e., fluoroscopy times, number of images, DAP, effective doses, and equivalent doses, show a wide range of values depending on the complexity of the patient case and the experience of the cardiologist. The mean fluoroscopy time, DAP, and E values for coronary angiography patients were approximately threefold lower than those for PCI patients; the number of images for CA was half that for PCI. The correlation between effective dose and DAP was excellent for both CA and PCI. The equivalent doses values were in good correlations with DAP values in CA examinations, with Pearson's coefficients ranging from 0.87 (stomach) to 0.99 (skin) and r(mean) = 0.94. The same analysis was performed for PCI procedures. In this case, the trends were only slightly worse because "r" ranged from 0.70 (stomach) to 0.92 (bone) and r(mean) = 0.85. Simple conversion coefficients to estimate equivalent doses to ten critical organs/tissues from DAP values, for both CA and PCI, were provided for avoiding the need to carry out detailed in-the-field analysis for all projections and for all patients. CONCLUSIONS: Measurements in-the-field of DAP values were carried out for two common cardiology procedures and effective doses were derived for each technique from detailed analysis of dose and projection data, using conversion factors provided by two different theoretical models. Equivalent doses to organs/tissues were also calculated using conversion factors proposed in the literature for different projections and cumulative conversion factors (H)T/DAP for ten organs/tissues were estimated.

[The shockwave: an ace in the hole?] / Lo shockwave: un asso nella manica?

In patients with severe calcified coronary lesions, angioplasty procedures are associated with significant technical problems and a higher rate of complications. Nowadays, intravascular lithotripsy represents a safe and effective system for the treatment of calcified coronary stenosis before stent deployment. In this article, we report three complex clinical or angiographic cases in which the use of coronary lithotripsy is not yet codified. Specifically, we discuss a case of stent underexpansion after primary angioplasty, a case of acute myocardial infarction due to left main subocclusive stenosis complicated by cardiogenic shock and a case of severely calcified plaque in a venous bypass graft. In these three cases, the use of shockwave was essential to ensure an optimal procedural result, in the absence of significant adverse clinical events.

Safety, efficacy and impact on frailty of mini-invasive radial balloon aortic valvuloplasty.

OBJECTIVE: The study was designed to: (1) confirm safety and feasibility of mini-invasive radial balloon aortic valvuloplasty (BAV); (2) assess its impact in terms of quality of life and frailty; and (3) evaluate whether changes in frailty after BAV are associated with death in patients undergoing transcatheter aortic valve implantation (TAVI). METHODS: 330 patients undergoing BAV in 16 Italian centres were prospectively included. The primary endpoint was the occurrence of major and minor Valve Academic Research Consortium (VARC)-2 bleeding. Secondary endpoints were scales of quality of life, frailty, evaluated at baseline and 30 days, and their relationship with the occurrence of all-cause death. RESULTS: BAV was performed by radial access in 314 (95%) patients. No VARC-2 major and six (1.8%) VARC-2 minor bleedings occurred in the study population. Quality of life, as well as frailty status, significantly improved 30 days after BAV. At 1 year, patients undergoing TAVI with baseline essential frailty toolset (EFT) <3 or achieving an EFT <3 after BAV had a comparable occurrence of all-cause death (15% vs 19%, p=0.58). On the contrary, patients with EFT ≥3 at 30 days despite BAV showed the worst prognosis (all-cause death: 40% vs 15% and 19%, p=0.006 and p=0.05, respectively). CONCLUSIONS: Mini-invasive radial BAV is safe, feasible and associated with a low rate of vascular complications. Patients improving EFT 30 days after BAV showed a favourable outcome after TAVI. TRIAL REGISTRATION NUMBER: NCT03087552.

Long-term effectiveness of early administration of glycoprotein IIb/IIIa agents to real-world patients undergoing primary percutaneous interventions: results of a registry study in an ST-elevation myocardial infarction network.

AIMS: To evaluate the clinical impact of early administration of glycoprotein IIb/IIIa agents (IIb/IIIa agents) in the context of a dedicated hub and spoke network allowing very prompt pharmacological/mechanical interventions. METHODS AND RESULTS: Using a prospective database, we conducted a cohort study of ST-elevation myocardial infarction (STEMI) patients (n = 1124) undergoing primary percutaneous coronary interventions (PPCIs) and IIb/IIIa agents administration (period, 2003-2006). Comparisons were planned between patients receiving early IIb/IIIa agents administration (in hub/spoke centre emergency departments or during ambulance transfer; early group, n = 380) or delayed administration (in the catheterization laboratory; late group, n = 744). The primary outcome measure was long-term overall mortality/re-infarction. Baseline characteristics of the two groups were largely comparable. Angiographically, early group patients more often achieved pre-PPCI TIMI Grade 2-3 and TIMI Grade 3 flow. Clinically, the early administration group experienced lower 2-year risk of unadjusted mortality/re-infarction (17 vs. 23%; P = 0.01). After adjustment for potential confounders, early administration was associated with favourable outcome in the overall population (HR = 0.71, P = 0.03) and in high-risk subgroups (TIMI risk index >25, HR = 0.64, P = 0.02; Killip class >1, HR = 0.54, P = 0.01). CONCLUSION: In patients treated by PPCI within a STEMI network setting, early administration of IIb/IIIa agents may provide long-term clinical benefits. Notably, these results appeared magnified in high-risk patients.

Multimodality Imaging of Purulent Pericarditis: Hints to Speed up Diagnosis and Promote Healing.

Purulent pericarditis is rare and usually associated with pneumonia, bacteremia, immunosuppression, and thoracic surgery. A timely diagnostic pericardiocentesis with dedicated maneuvers to improve the effectiveness of drainage and pericardial fibrinolytic rinsing can improve prognosis and prevent a surgical pericardiectomy. Imaging offers useful clues for a more aggressive approach.

No-Reflow Complicating Chronic Total Occlusion Coronary Revascularization.

OBJECTIVES: To assess the incidence of no-reflow in patients undergoing chronic total occlusion (CTO) percutaneous coronary intervention (PCI), analyze possible causes and differential diagnoses, and identify useful management approaches. METHODS: In this multicenter observational study, all CTO-PCIs performed between January 2018 and April 2019 were reviewed to collect no-reflow complications, defined as Thrombolysis in Myocardial Infarction (TIMI) flow ≤1 in a patent epicardial artery. Patient clinical, anatomical, and procedural characteristics were analyzed. RESULTS: Out of 461 PCIs, two (0.43%) were complicated by no-reflow. In 1 case, PCI was performed on a long segment of the right coronary artery, after use of a dissection-re-entry technique by knuckle wiring. In the second patient, no-reflow developed after proximal left anterior descending coronary artery stenting, with a short subintimal tracking. Intravascular ultrasound was used to exclude complications in the epicardial vessel in both cases. Distal embolization seems the most plausible cause, and intracoronary adenosine effectively improved flow. Both patients had a type 4a myocardial infarction, asymptomatic in the first case, and associated with chest pain, electrocardiographic changes, and new regional wall-motion abnormality at echocardiography in the second case. CONCLUSIONS: No-reflow in CTO recanalization is rare, but associated with a high risk of periprocedural myocardial infarction, with incomplete protection from ischemia offered by the pre-existing collateral network.