Stamatios Lerakis

Predictive factors, management, and clinical outcomes of coronary obstruction following transcatheter aortic valve implantation: Insights from a large multicenter registry

OBJECTIVESnThis study sought to evaluate the main baseline and procedural characteristics, management, and clinical outcomes of patients from a large cohort of patients undergoing transcatheter aortic valve implantation (TAVI) who suffered coronary obstruction (CO).nnnBACKGROUNDnVery little data exist on CO following TAVI.nnnMETHODSnThis multicenter registry included 44 patients who suffered symptomatic CO following TAVI of 6,688 patients (0.66%). Pre-TAVI computed tomography data was available in 28 CO patients and in a control group of 345 patients (comparisons were performed including all patients and a cohort matched 1:1 by age, sex, previous coronary artery bypass graft, transcatheter valve type, and size).nnnRESULTSnBaseline and procedural variables associated with CO were older age (p < 0.001), female sex (p < 0.001), no previous coronary artery bypass graft (p = 0.043), the use of a balloon-expandable valve (p = 0.023), and previous surgical aortic bioprosthesis (p = 0.045). The left coronary artery was the most commonly involved (88.6%). The mean left coronary artery ostia height and sinus of Valsalva diameters were lower in patients with obstruction than in control subjects (10.6 ± 2.1 mm vs. 13.4 ± 2.1 mm, p < 0.001; 28.1 ± 3.8 mm vs. 31.9 ± 4.1 mm, p < 0.001). Differences between groups remained significant after the case-matched analysis (p < 0.001 for coronary height; p = 0.01 for sinus of Valsalva diameter). Most patients presented with persistent severe hypotension (68.2%) and electrocardiographic changes (56.8%). Percutaneous coronary intervention was attempted in 75% of the cases and was successful in 81.8%. Thirty-day mortality was 40.9%. After a median follow-up of 12 (2 to 18) months, the cumulative mortality rate was 45.5%, and there were no cases of stent thrombosis or reintervention.nnnCONCLUSIONSnSymptomatic CO following TAVI was a rare but life-threatening complication that occurred more frequently in women, in patients receiving a balloon-expandable valve, and in those with a previous surgical bioprosthesis. Lower-lying coronary ostium and shallow sinus of Valsalva were associated anatomic factors, and despite successful treatment, acute and late mortality remained very high, highlighting the importance of anticipating and preventing the occurrence of this complication.

A Practical Guide to Multimodality Imaging of Transcatheter Aortic Valve Replacement

The advent of transcatheter aortic valve replacement (TAVR) is one of the most widely anticipated advances in the care of patients with severe aortic stenosis. This procedure is unique in many ways, one of which is the need for a multimodality imaging team-based approach throughout the continuum of the care of TAVR patients. Pre-procedural planning, intra-procedural implantation optimization, and long-term follow-up of patients undergoing TAVR require the expert use of various imaging modalities, each of which has its own strengths and limitations. Divided into 3 sections (pre-procedural, intraprocedural, and long-term follow-up), this review offers a single source for expert opinion and evidence-based guidance on how to incorporate the various modalities at each step in the care of a TAVR patient. Although much has been learned in the short span of time since TAVR was introduced, recommendations are offered for clinically relevant research that will lead to refinement of best practice strategies for incorporating multimodality imaging into TAVR patient care.

Evaluation of Right Intraventricular Dyssynchrony by Two-Dimensional Strain Echocardiography in Patients With Pulmonary Arterial Hypertension

BACKGROUNDnRight ventricular (RV) function has major prognostic implications for patients with pulmonary arterial hypertension (PAH). Intraventricular dyssynchrony might play an important role in RV dysfunction in these patients.nnnMETHODSnThirty-six patients with PAH without right bundle branch block (mean age 44 +/- 14 yr, 24 women) and 39 controls (mean age 43 +/- 18 yr, 26 women) were evaluated. Global and segmental RV longitudinal deformation parameters were recorded by 2-dimensional strain echocardiography from apical 4-chamber views using a 6-segment RV model. The standard deviation of the heart rate-corrected intervals from QRS onset to peak strain for the 6 segments (RV-SD(6)) was used to quantify right intraventricular dyssynchrony.nnnRESULTSnRV-SD(6) was significantly higher in patients with PAH compared with controls (63 +/- 21 vs 25 +/- 15ms, P < .001). Dyssynchrony in patients with PAH was found to derive mainly from delayed contraction of the basal and mid RV free wall. In patients with PAH, RV-SD(6) was strongly correlated with RV fractional area change (beta = -.519, P = .002), RV myocardial performance index (beta = .427, P = .009), and RV global strain (beta = .512, P = .002); in models controlling for RV systolic pressure, RV size, and QRS duration, RV-SD(6) was still an independent predictor of RV fractional area change (beta = -.426, P = .005) and RV global strain (beta = .358, P = .031). RV function was significantly worse in the subgroup of patients with PAH (n = 25) with RV-SD(6) > 55 ms (the upper 95% limit in controls).nnnCONCLUSIONnRight intraventricular dyssynchrony, as quantified by 2-dimensional strain echocardiography, is prevalent in PAH and is associated with more pronounced RV dysfunction. The clinical implications of these findings remain to be determined in follow-up studies.

Emerging applications for transseptal left heart catheterization old techniques for new procedures.

Transseptal (TS) catheterization was introduced in 1959 as a strategy to directly measure left atrial (LA) pressure. Despite acceptable feasibility and safety, TS catheterization has been replaced by indirect measurements of LA pressure using the Swan-Ganz catheter. Today, TS puncture is rarely performed for diagnostic purposes but continues to be performed for procedures such as balloon mitral valvuloplasty, antegrade balloon aortic valvuloplasty, and ablation of arrhythmias in the LA. Thus, the art of TS puncture has been lost, except in centers that perform these procedures with regularity. Recently, there has been a renewed interest in the TS technique because of emerging therapeutic procedures for structural heart disease and atrial fibrillation ablation. Invasive cardiologists will have to refamiliarize themselves with the TS technique, newer TS devices, and advanced ultrasound imaging for guidance of the procedure.

Can balloon aortic valvuloplasty help determine appropriate transcatheter aortic valve size

OBJECTIVESnWe sought to study the potential role of balloon aortic valvuloplasty (BAV) in sizing the aortic annulus in patients before transcatheter heart valve (THV) implantation.nnnBACKGROUNDnDespite clinicians growing experience with THV procedures, the best method of annulus sizing remains unclear.nnnMETHODSnTwenty-three patients with aortic stenosis (<1.0 cm(2)) who were undergoing surgical valve replacement were enrolled. Pre-operative echocardiographic measurements of the annulus and computed tomography measurements of valve calcium were made. Intraoperatively, a valvuloplasty balloon of known size and inflatable pressure was inserted into the aortic valve and inflated. The development of intraballoon pressure in addition to the nominal inflation pressure (AIBP) reflected the apposition of balloon and valve. Surgical annulus was measured by cylindrical sizers.nnnRESULTSnIn patients with tricuspid valves, AIBP was generated in 11 of 12 patients when the balloon diameter was greater than the surgically measured annulus, regardless of leaflet calcification (2 of 10 patients when balloon < or = surgical annulus). In bicuspid valves, high AIBP ( approximately 1 atm) was encountered with balloons that were within 1 mm of annulus size, and leaflet dehiscence occurred with larger balloons (n = 2 patients). Annulus size was underestimated by transthoracic echocardiogram and transesophageal echocardiogram compared with surgery (p < 0.001): transthoracic echocardiogram = 21.5 +/- 1.8 mm, transesophageal echocardiogram = 22.0 +/- 1.6 mm and surgical = 23.2 +/- 1.9 mm (range 20 to 27 mm, mode 22 mm).nnnCONCLUSIONSnThese data suggest that measuring AIBP during balloon aortic valvuloplasty in tricuspid valves is an important adjunctive measurement of the aortic annulus and may help in determining the appropriate THV size.

Use of Balloon Aortic Valvuloplasty to Size the Aortic Annulus Before Implantation of a Balloon-Expandable Transcatheter Heart Valve

OBJECTIVESnOur aim was to describe the use of balloon aortic valvuloplasty (BAV) to select proper transcatheter heart valve (THV) size.nnnBACKGROUNDnTransesophageal echocardiogram (TEE) measurement alone of the aortic annulus may not be adequate to select a THV size. BAV can more accurately size the aortic annulus. We report our experience using this strategy in patients undergoing THV implantation.nnnMETHODSnTwenty-seven patients underwent sizing of the aortic annulus by BAV and TEE. We implanted the minimal THV size that was greater than the annulus measured by BAV.nnnRESULTSnThe annulus measured by TEE was 21.3 +/- 1.6 mm and by BAV was 22.6 +/- 1.8 mm (p < 0.001). The number of balloon inflations was 2.7 +/- 0.7 (range 2 to 4), and the balloon sizes used were 22.0 +/- 1.8 mm (range 20 to 25 mm). Fourteen patients (52%) required upsizing of the initial balloon suggested by TEE; rapid pacing duration was 8 +/- 1.3 s (range 6 to 11 s). No change in aortic insufficiency or hemodynamic instability occurred with BAV. Fifteen patients (56%) received a 23-mm THV; 12 patients a 26-mm THV. No coronary occlusion, annular damage, or THV embolization occurred. Paravalvular leak was grade <or=1 in all patients. In 7 patients (26%), balloon sizing resulted in selection of a specific THV size that could not be done by TEE alone.nnnCONCLUSIONSnBAV sizing of the aortic annulus is safe and is an important adjunct to TEE when selecting THV size. Implanting the minimal THV greater than the BAV annulus size resulted in no adverse events. These data suggest that use of BAV for THV selection may improve the safety and efficacy of THV implantation.

Intentional Percutaneous Laceration of the Anterior Mitral Leaflet to Prevent Outflow Obstruction During Transcatheter Mitral Valve Replacement: First-in-Human Experience

OBJECTIVESnThis study sought to use a new catheter technique to split the anterior mitral valve leaflet (AML) and prevent iatrogenic left ventricular outflow tract (LVOT) obstruction immediately before transcatheter mitral valve replacement (TMVR).nnnBACKGROUNDnLVOT obstruction is a life-threatening complication of TMVR, caused by septal displacement of the AML.nnnMETHODSnThe procedure was used in patients with severe mitral valve disease and prohibitive surgical risk. Patients either had prior surgical mitral valve ring (nxa0= 3) or band annuloplasty (n = 1) or mitral annular calcification with stenosisxa0(nxa0= 1). Iatrogenic LVOT obstruction or transcatheter heart valve dysfunction was predicted in all based on echocardiography andxa0computed tomography. Transfemoral coronary guiding catheters directed an electrified guidewire across the center and base of the AML toward a snare in the left atrium. The externalized guidewire loop was then electrified to lacerate the AMLxa0along the centerline from base to tip, sparing chordae, immediately before transseptal TMVR.nnnRESULTSnFive patients with prohibitive risk of LVOT obstruction or transcatheter heart valve dysfunction from TMVR successfully underwent LAMPOON, with longitudinal splitting of the A2 scallop of the AML, before valve implantation. Multiplane computed tomography modeling predicted hemodynamic collapse from TMVR assuming an intact AML. However, critical LVOT gradients were not seen following LAMPOON and TMVR. Doppler blood flow was seen across transcatheter heart valve struts that encroached the LVOT, because the AML was split. Transcatheter heart valve function was unimpeded.nnnCONCLUSIONSnThis novel catheter technique, which resembles surgical chord-sparing AML resection, may enablexa0TMVRxa0inxa0patients with prohibitive risk of LVOT obstruction or transcatheter heart valve dysfunction.

Contrast-induced acute kidney injury in patients with renal dysfunction undergoing a coronary procedure and receiving non-ionic low-osmolar versus iso-osmolar contrast media

Background:Although the superiority of low-osmolar over high-osmolar contrast agents in prevention of contrast-induced acute kidney injury (CI-AKI) is generally accepted, the relative nephrotoxicity of iso-osmolar over low-osmolar agents has not yet clearly defined. We examined the incidence of CI-AKI according to the type of contrast agent used in a randomized study of ascorbic acid for CI-AKI prevention. Methods:A total of 222 patients with baseline serum creatinine ≥1.2 mg/dL who were undergoing a coronary procedure and who were randomized to receive ascorbic acid or placebo were evaluated. The iso-osmolar agent iodixanol was used in 144 patients, whereas low-osmolar non-ionic agents were used in 78 patients (iomeprol, n = 40; iobitridol, n = 30; iopentol, n = 8). CI-AKI was defined by an absolute serum creatinine increase of ≥0.5 mg/dL or a relative increase of ≥25% measured 2 to 5 days after the procedure. Results:The groups of patients who received iso-osmolar and low-osmolar non-ionic agents were well balanced in terms of demographic, clinical, and procedural characteristics. The overall CI-AKI incidence was 14.6% for the iso-osmolar iodixanol versus 14.1% for the combined low-osmolar non-ionic agents (iomeprol, 10%; iobitridol, 10%; iopentol, 50%). For iodixanol, the incidence of CI-AKI was 7.4% for patients randomized to receive ascorbic acid and 21.6% for placebo (P = 0.02). The corresponding incidences for the low-osmolar non-ionic agents were 9.1% and 20.6%, respectively (P = 0.19). Conclusion:No differences in CI-AKI incidence were apparent among patients receiving non-ionic iso-osmolar iodixanol and non-ionic low-osmolar contrast agents. The preventative effect of ascorbic acid was also similar.

Transesophageal echocardiography to help position and deploy a transcatheter heart valve.

TRANSCATHETER AORTIC VALVE IMPLANTATION (TAVI) IS A CLINICALLY ACCEPTED PRACTICE IN EUROPE for patients with high or prohibitive surgical risk and is undergoing clinical investigation in the U.S. and Canada. Some investigators have utilized transesophageal echocardiography (TEE) to select

Aortic stenosis: a contemporary review.

Abstract: Aortic stenosis (AS) is the most common valvular disease in the western world affecting mainly individuals older than 60 years. It is recognized as an indolent disease characterized by years to decades of slow progression followed by rapid clinical deterioration and high mortality once symptoms develop. Medical therapies for AS remain ineffective with surgical aortic valve replacement (AVR) remaining the only proven effective long-term treatment. The advancement in transcatheter AVR has revolutionized the treatment of inoperable severe AS and holds promise for future widespread use as more long-term experience is established. The authors review the natural history of AS presentation with a special emphasis on management of severe AS and advancement in transcatheter AVR.