Coronary Artery Occlusion during Transcatheter Aortic Valve Implantation: Early Recognition Have Better Outcome.

Transcatheter aortic valve implantation (TAVI) is one of the rapidly evolving treatment strategies for severe aortic stenosis. Included in this category are inoperable, high, intermediate, and low surgical risk patients. It has varying types of complications that may require urgent surgical or transcatheter interventions to prevent procedural mortality and morbidity. Coronary artery occlusion is a rare and dreaded complication of TAVI. Here, we report a 73-year-old man who was diagnosed with severe aortic stenosis and underwent transfemoral TAVI. Unfortunately, during preimplantation balloon valvuloplasty, the patient developed severe hypotension along with ischemic changes on the electrocardiographic monitor. Promptly, coronary angiography was performed which revealed complete occlusion of the left anterior descending artery secondary to embolic debris. He was successfully rescued by manual aspiration thrombectomy (MAT). MAT results in restoration of coronary flow and reversal of shock condition before completing TAVI procedure. Copyright:

INTRODUCTION

Recently, transcatheter aortic valve implantation (TAVI) has emerged as a noninferior alternative to surgical aortic valve replacement in high-, intermediate-, and low-risk patients when a transfemoral approach is available.[1] Although the success is achieved in the vast majority of patients and the complications rates are low, this procedure can be associated with several potential adverse events. Among these is the rare event of coronary obstruction that occurs in approximately 0.4% of TAVI procedures in native severe aortic valve stenosis.[23]

We report a rare case of TAVI complicated by acute left anterior descending (LAD) coronary artery obstruction and cardiogenic shock due to embolic debris migration after pre-implantation balloon valvuloplasty. The patient was without recognized anatomical risk factors for coronary obstruction.

CASE PRESENTATION

A 73-year-old man, known to have type 2 diabetes mellitus, was admitted to the hospital for elective TAVI after heart team recommendation. He was recently discovered to have severe aortic stenosis, which was detected during hospitalization for acute pulmonary edema 1 month prior to admission. The patient had a feeling of impending doom and symptoms of heart failure New York Heart Association, class III, over the last 3 weeks. Echocardiography evaluation showed severe aortic valve stenosis (mean gradient 47 mmHg, aortic valve area 0.6 cm2), trivial aortic valve regurgitation, and left ventricular ejection fraction (LVEF) of 48% [Figure 1a]. Significant coronary artery disease was excluded by coronary angiography [Figure 1b].

Figure 1

(a) Preprocedural transesophageal echocardiography showing a continuous wave Doppler image of severe aortic stenosis. (b) Coronary angiogram showing normal perfusion of left coronary arteries before transcatheter aortic valve implantation

Following the standard protocol for TAVI workup, a cardiac computerized tomography angiography (CTA) was performed, which suggested adequate coronary heights (16 mm for left main coronary and 19 mm for the right coronary artery [RCA] ostium), aortic annulus perimeter of 82.9 mm, sinuses of Valsalva measurements of 29.3 mm × 31.7 mm × 28.0 mm, with heavily calcified aortic valve leaflets [Figure 2]. Finally, we decide to deploy a 29 mm bioprosthetic valve (Medtronic CoreValve™).

Figure 2

Coronary computed tomography angiography showing the size of (a) Aortic annulus perimeter, (b) sinuses of valsalva diameter, (c) left ventricular outflow tract perimeter, (d) Distance of the right coronary ostia from aortic annulus plane. (e) Distance of the left main coronary ostia from aortic annulus plane. (f) Calcification of aortic cusps

Transcatheter aortic valve implantation procedure

The procedure was performed under general anesthesia and TEE guidance. Right and left femoral arteries were accessed with 6-french sheaths. The transvenous pacing was placed under fluoroscopic guidance in the right ventricle through the right internal jugular vein through 6-french sheath.

Balloon valvuloplasty was performed after giving 90 units per kg of unfractionated heparin to achieve ACT level of 280. A 25 mm balloon (NuMED NuCLEUS™) was advanced through the right femoral artery sheath and inflated under rapid ventricular pacing at 160 beats per minute [Figure 3a] which was associated with mild balloon instability and movement of the balloon in and out at annular plane/left ventricular outflow tract-level during the maximum inflation because of inadequate rapid pacing. Seconds later, the patient developed severe hypotension (60/40 mmHg) and bradycardia (40 bpm) along with dynamic ST-segment changes on the monitor. Temporary pacing was activated, and the patient was resuscitated with vasopressors to sustain the hemodynamics. However, the patient remained hypotensive despite inotropic support. Angiography of the aortic root was performed which demonstrated patent RCA and left main coronary artery Ostia [Figure 3b]. Pericardial tamponade and aortic dissection were both excluded immediately by transesophageal echocardiography which also demonstrated severe reduction of the left ventricular function along with a hypokinetic anterior wall, in which coronary obstruction was suspected.

Figure 3

(a) X-ray fluoroscopy demonstrating balloon valvuloplasty for the native aortic valve (white arrow). (b) Aortic angiogram showed the flow of contrast to the main right and left coronary arteries. (white arrows). (c) Selective left coronary artery angiogram demonstrated total occlusion of middle left anterior descending artery (white arrow). (d) X-ray fluoroscopy demonstrating thrombus aspiration by using the aspiration catheter. (e) Left coronary artery angiogram showing successful left anterior descending angioplasty with TIMI III flow (white arrow). (f) Fluoroscopic view of Evolut-R prosthesis after valve release (white arrow)

Instantaneously, coronary angiography of the left coronary arteries was performed, which depicted total occlusion of proximal LAD artery by an embolic material [Figure 3c]. Promptly, a rescue angioplasty using XB guiding catheter and choice PT extra support wire, the lesion was crossed successfully. Manual aspiration of the culprit thrombus was performed using Export AP aspiration catheter [Figure 3d] resulting in successful coronary reperfusion (TIMI 3 flow) [Figure 3e], restoration of LV systolic function, and rapid hemodynamic improvement.

Subsequently, a self-expanding 29 mm bioprosthetic valve (Evolut-R) was deployed within the native aortic valve [Figure 3f]. The patient was then shifted to the coronary care unit where he was extubated and weaned off inotropic support within few hours. The predischarge transthoracic echocardiography showed mild reduced LV systolic function (LVEF) of 47% with marked improvement of the aortic transvalvular gradient to 8 mmHg with trivial paravalvular leak. The patient was discharged home after 7 days in NYHA I clinical status. He was evaluated after 1 month at the outpatient clinic, where he was completely asymptomatic.

DISCUSSION

TAVI is a rapidly adopted modality in the treatment of severe aortic stenosis and has expanded from nonoperable to high, intermediate, and low surgical risk patients.[4] Nonetheless, TAVI still carries risks for complications that may critically influence the outcome, including coronary artery obstruction which occurs in <1% of native valve interventions with associated mortality up to 50%.[567]

Coronary artery occlusion tends to involve the left coronary artery more frequently than the RCA because of the naturally higher ostial takeoff of the RCA.[8]

Coronary obstruction during TAVR for native aortic valve stenosis can occur due to anatomical or procedural related factors. The established anatomical risk factors for coronary occlusion during TAVI in severe native aortic valve stenosis include low origin of the coronary arteries (<10 mm), narrow sinus of Valsalva (<28 mm), calcium burden, and location of calcium on the cusp.[91011]

In the present case report, coronary obstruction was probably due to inadequate rapid ventricular pacing and excessive movement of balloon in the aortic root during the preimplantation balloon valvuloplasty despite adequate ACT level. This resulted in balloon instability at the time of maximal balloon inflation, raising the suspicion of displacement of the calcific emboli or thrombus from the native aortic valve cusps to the LAD through the left coronary ostium. To the best of our knowledge, this is the first reported case of TAVI with coronary obstruction resulting from balloon instability during the preimplantation balloon valvuloplasty in the absence of anatomical risk factors.

Preprocedural assessment of aortic valve anatomy using multidetector computed tomography is a crucial step to minimize and anticipate the potential risk of complications including aortic annulus rupture, perivalvular leak, and coronary occlusion.[81213] Eventually, for patients who are deemed at considerable risk for coronary occlusion pre-TAVI CTA evaluation, transcatheter techniques such as coronary protection with a standard guidewire, placing a snorkel stent, or per performing BASILICA procedure is advisable to prevent and treat potential occlusion.[14]

In our patient, the risk of coronary occlusion was low based on his pre-TAVI CTA evaluation.

Intraprocedural coronary occlusion should be suspected in the presence of high-grade heart blocks, severe hypotension, lethal ventricular arrhythmias or dynamic ST-segment changes. Therefore, a prompt angiographic assessment of coronary patency is imperative and rescue angioplasty is the mainstay therapy to prevent fatal complications.

CONCLUSION

Coronary obstruction during TAVI is a rare entity, but life-threatening complication with a high fatality rate. Therefore, prompt recognition and intervention are critical for overall survival. Moreover, careful patient selection and evaluation with preprocedural CTA is crucial to predict procedural complications.

In our case, coronary artery obstruction occurred in the absence of recognized anatomical risk factors.

Consequently, the authors believe that maintaining a stable balloon position throughout inflation by adequate ventricular pacing during balloon valvuloplasty is important to reduce the risk for coronary occlusion.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initial s will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.