High-Risk Chronic Total Occlusion Percutaneous Coronary Interventions Assisted With TandemHeart

Abstract: Background. Hemodynamic support is increasingly utilized to avoid hemodynamic collapse during high-risk chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Intermediate-term outcomes of Tandem Heart (TH)-supported CTO-PCI have not been previously reported. Methods. We retrospectively evaluated procedural and clinical outcomes in consecutive patients undergoing TH-assisted CTO-PCI at our institution from April 1, 2016 to January 30, 2019. Results. Thirteen TH-assisted CTO-PCIs (25%) were performed during the study period. TH was placed before the PCI in all procedures. The most common reason for hemodynamic support was the use of retrograde CTO-PCI technique in the setting of left ventricular dysfunction (38%). Eleven patients (92%) had decreased left ventricular function with severe congestive heart failure symptoms before the procedure. The CTO vessel treated was the right coronary artery in 38% of patients. Retrograde approach was utilized in 6  PCIs (46%). Technical success was achieved in 12 PCIs (92%) despite very complex and very difficult CTO lesions, as indicated by a median J-CTO score of 3 and Progress CTO score of 2. Procedural success was achieved in 10 patients (77%). TH was removed at the completion of PCI in 11 procedures (85%). There were no major bleeding complications; however, one patient developed arteriovenous fistula at the arterial cannula insertion site. One patient had coronary perforation with hemodynamic compromise requiring pericardiocentesis. One patient died of cardiogenic shock, secondary to right ventricular wall hematoma. Conclusions. TH can be used for hemodynamic support during CTO-PCI to achieve a very high technical success rate. 

Key words: cardiogenic shock, hemodynamic support, high-risk PCI

Coronary chronic total occlusions  (CTOs) are found in about 20% of patients with coronary artery disease.^1-3 These patients often have multivessel coronary artery disease as well as left ventricular (LV) dysfunction and are deemed to be high risk for surgical revascularization.^1-3 Percutaneous coronary intervention (PCI) of CTOs in patients with reduced LV function has been shown to improve LV function.^4,5 Retrograde CTO-PCI technique is associated with ischemia during the procedure, which can result in hemodynamic collapse. Recently, hemodynamic support has been utilized during CTO-PCI to avoid hemodynamic collapse and improve patient tolerance to the transient ischemia during the procedure.^6,7 TandemHeart (TH; LivaNova), a percutaneous LV-assist device using a 21 Fr left atrial cannula to drain oxygenated blood from the left atrium, and an arterial cannula (15, 17, or 19 Fr) for returning blood to the arterial system, has been used for high-risk PCI for over a decade.^8,9 The use of hemodynamic support during CTO-PCI was previously reported by Danek et al.⁶ Most patients in the study received Impella (Abiomed) for hemodynamic support without detailed description of the subgroup that received TH support; in addition, outcomes data in the study were limited to hospital discharge.⁶ Herein, we report on the use of TH-assisted CTO-PCI and provide 30-day and 6-month outcomes. 

Methods

Patient population and data collection. We retrospectively evaluated the procedural and clinical outcomes in patients undergoing TH-assisted CTO-PCI at our institution from April 1, 2016 to January 30, 2019. Data were collected retrospectively by reviewing the hospital’s electronic health records, which included patient demographics, comorbidities, presenting symptoms, procedural details, and clinical outcomes. The database was further augmented with collection of follow-up data via telephone call and/or chart review to assess the 30-day and 6-month survival rates. All data were collected and entered in an Excel sheet. The study was approved by the institutional review board at Henry Ford Hospital in Detroit, Michigan. 

Definitions. Coronary CTOs are defined as 100% occlusions with Thrombolysis in Myocardial Infarction (TIMI) 0 flow for at least 3 months.⁹ Technical success was defined as angiographic evidence of <30% residual stenosis with restoration of TIMI 3 flow in the CTO vessel. Major adverse cardiovascular event (MACCE) was defined as the composite of death, myocardial infarction (MI), recurrent cardiac symptoms requiring repeat target-vessel PCI or coronary artery bypass graft (CABG) surgery, cardiac tamponade requiring pericardiocentesis or surgery, and stroke. Procedural success was defined as technical success without the incidence of in-hospital MACCE. MI was defined according to the Third Universal Definition of Myocardial Infarction.¹¹ Major bleeding events were defined as any overt bleeding that met criteria for Bleeding Academic Research Consortium (BARC)-3 or higher categories.¹² 

Statistical analysis. Continuous data are presented as mean ± standard deviation or median (range). Categorical data are presented as frequencies and percentages. All data were analyzed using SPSS, version 24.0 (IBM).

Results

A total of 395 CTO-PCIs were performed at our institution during the study period; fifty-two of these procedures (13%) were performed with hemodynamic support using advanced mechanical circulatory support devices. TH was utilized in 13 CTO-PCIs (25%) in 12 patients (1 patient underwent TH-assisted CTO-PCI twice in the study period). Baseline patient characteristic data are presented in details in Table 1.  The majority of patients were Caucasian men. Median patient age was 71 years. Six patients (50%) had prior MI and 4 (33%) had prior CABG. Eleven patients (92%) had multivessel coronary artery disease.

Eight patients (67%) had decreased LV systolic function (LV ejection fraction <30%). Eleven patients (92%) had New York Heart Association class III or IV congestive heart failure symptoms before the procedure. Two patients with normal LV systolic function received TH during the CTO-PCI procedure; one had ACS with cardiac arrest and the other had persistent hypotension after conscious sedation. TH was placed before PCI in all procedures. 

The procedural data related to all 13 CTO-PCIs are presented in Table 2. The most common reason for hemodynamic support was the use of retrograde technique in the setting of LV dysfunction in 5 patients (38%). Femoral access was used for both left atrial and arterial TH cannulas. Vasopressors were required during 2 PCIs (15%) despite using TH; the TH device was removed at the completion of PCI in 11 out of 13 procedures (85%).  

The indication for CTO-PCI was angina despite medical therapy in 9 patients (69%) and ischemia reduction in 7 patients (54%). Radial approach was utilized in 12 PCIs (92%), and half of these PCIs were performed with bilateral radial accesses.  The CTO vessel treated was the right coronary artery in 38%, followed by the left circumflex and the left anterior descending coronary artery (31% each). Retrograde CTO-PCI technique was utilized in 46% of PCIs and antegrade wire escalation was the most successful crossing strategy (53%). Technical success was achieved in 92% of PCIs despite very complex and very difficult CTO lesions, as indicated by median J-CTO score of 3 and progress CTO score of 2. This cohort was also at the highest possible risk of periprocedural complication, as indicated by a median Progress CTO Complications score of 5. Drug-eluting stents were used in all but 2 PCIs (1 received subintimal plaque modification with balloon angioplasty alone, 1 lesion couldn’t be crossed). More than 1 vessel (CTO or non-CTO) was treated in 4 procedures (31%). The procedures were long, with median procedure time of 256 minutes and median fluoroscopy time of 76 minutes; median contrast volume was 230 mL. One patient (8%) developed arteriovenous fistula at the arterial cannula insertion site; there were no other vascular complications or major bleeding. All left atrial cannulas were 21 Fr; all arterial cannulas were 17 Fr, except in 1 patient who received a 15 Fr arterial cannula.

All TH decannulations were performed in the catheterization laboratory. Iliac artery balloon occlusion was utilized in 10 patients (77%) to achieve “dry closure” in all arterial access sites. Arterial access closure was achieved using two Perclose ProGlides (Abbott Vascular) in 4 patients (30%) and in combination with 8 Fr Angio-Seal (Terumo) in 9 patients (70%). Final iliofemoral angiogram was performed in 12  patients (92%). Venous access hemostasis was achieved with either Perclose ProGlide or figure-of-eight suture.

Procedure success was achieved in 10 patients (77%). Median length of stay was 3 days. One patient had coronary perforation with hemodynamic compromise requiring pericardiocentesis. One patient developed severe persistent cardiogenic shock secondary to right ventricular wall hematoma and died after prolonged intensive care unit stay; thus, in-hospital survival rate was 92%. Ten of the remaining patients went on to live at least 30 days; thus, our 30-day survival rate was 83%. Overall 6-month survival rate was 75%. 

Discussion

We report a single-center experience of 13 consecutive CTO-PCIs performed in 12 patients with hemodynamic support utilizing TH. The technical success achieved was 92% despite J-CTO and Progress CTO scores indicating very difficult and complex lesions. Procedural success rate was 77%. The procedure times were long (median time >4 hours). Patients tolerated the procedure well, with only 15% of patients requiring vasopressor use during PCI. Despite large-bore cannulas in both venous and arterial access sites, there was only 1 vascular access complication, without any major bleeding or TH-related complications; however, one patient (8%) had coronary perforation with hemodynamic compromise requiring pericardiocentesis. One patient developed severe persistent cardiogenic shock secondary to right ventricular wall hematoma and died. Eleven patients (92%) were discharged from the hospital after a reasonable length of stay. All but 1 of the remaining patients survived at least 30 days. Overall 6-month survival was 75%. This series supports that TH-supported CTO-PCI is feasible despite highly complex coronary lesions in a high-risk cohort.  

Hemodynamic collapse during CTO-PCI remains a significant concern, especially when retrograde approach is utilized in patients with pre-existing LV dysfunction and patients with multivessel coronary artery disease. Hemodynamic support is increasingly utilized to avoid hemodynamic collapse and improve patient tolerance to the transient ischemia during the procedure. Impella CP is the most frequently used device;^6,7 however, TH can be used in clinical scenarios when Impella use is contraindicated, such as in patients with LV thrombus, mechanical aortic valve, etc.¹³ TH provides more flow than Impella CP, which could be critical in minimizing predicted cardiac output deficit (body surface area x 2.2 = cardiac output) during the procedure if patients are to be totally dependent on the device. In addition, an Impella catheter may cause over-crowding of the aortic root as well as unwanted interactions with guide catheters (especially Amplatz guide catheters) during CTO-PCI. TH eliminates this problem and can therefore better facilitate guide-catheter manipulation, especially in patients with small aortic roots. TH has been used for hemodynamic support during high-risk PCI since early 2000.^8,9 Aragon et al⁸ reported a case series of 8 patients with LV dysfunction and multivessel coronary artery disease who underwent multivessel or left main PCI with TH hemodynamic support without any procedural complications. Similarly, Alli et al⁹ reported the largest case series of 54 patients undergoing high-risk PCI with TH support; left main and multivessel PCI was performed in 62% of patients with 97% procedural success rate. However, it is unclear if these case series included any CTO-PCI. More recently, Danek et al⁶ reported the use of elective mechanical circulatory support in 11 patients undergoing CTO-PCI with TH. However, they offered very little information regarding the indication, procedural details, and outcomes in the TH cohort. Our series is the first to report procedural outcomes as well as 30-day and 6-month clinical outcomes of TH-assisted CTO-PCI. All patients tolerated the procedure fairly well, with only 15% of patients requiring vasopressor use during PCI. We were able to achieve a 92% technical success rate. In-hospital MACCE rate was 15%, which is about 3-fold higher than the previously reported findings in patients undergoing CTO-PCI with elective hemodynamic support.⁶ Most of the complications were related to the CTO-PCI procedure. This is likely due to the anatomical and procedural complexities in our very sick patient population, as indicated by the Progress CTO Complications score. 

Previous case series have reported vascular complication rates of up to 13% when TH was utilized for hemodynamic support.⁹ In our series, there was only one vascular complication, which was detected as an incidental finding, without any major bleeding or TH-related complications. This is secondary to meticulous planning with iliofemoral angiography, use of closure devices, and the use of balloon tamponade from contralateral femoral or radial access during TH decannulation. It is also important to note that there is a very steep learning curve regarding implanting and explanting these devices, and the procedure involves challenging skillsets such as large-bore access and atrial transseptal puncture. Needless to say, the training and experience of support staff in the catheterization laboratory as well as cardiac intensive care also play a critical role. 

Study limitations. In addition to the influence of missing and unmeasured confounders, the sample size of our study is small.  There was no fixed protocol for device implantation or explantation. We did not have available hemodynamic data to draw any inference on the effect of TH on patient hemodynamics during CTO-PCI. Less than 50% of patients received right heart catheterization prior to TH insertion. In addition, our study cannot provide any insight into whether TH is better compared with other available hemodynamic support devices during CTO-PCI. Our study involves a highly selected group of patients who underwent a very challenging and complex procedure in a quaternary-care center with a high level of experience in hemodynamic support and CTO-PCI. Therefore, the result of this series is not generalizable to centers or operators with different experience levels and patient populations. 

Conclusion

TH can be used for hemodynamic support during CTO-PCI to achieve a very high technical success rate in the highest-risk subset of patients. However, the safety and efficacy of CTO-PCI needs to be further evaluated in prospectively designed studies with larger sample sizes and a fixed protocol to assess its effect on patient hemodynamics as well as clinical outcomes in comparison with other available devices for hemodynamic support.  

References 

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From the Division of Cardiology, Department of Internal Medicine, Henry Ford Hospital, Detroit, Michigan.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Alaswad reports consultant income from LevaNova, Boston Scientific, Abbott Vascular, and Cardiovascular Systems, Inc; intellectual property (antegrade hemodynamic support). Dr Basir reports consultant income from Abiomed, Abbott Vascular, Cardiovascular Systems, Inc, Chiesi, and Zoll. Dr O’Neill reports personal fees from Abiomed. The remaining authors report no conflicts of interest regarding the content herein.

Manuscript submitted August 18, 2019, provisional acceptance given August 27, 2019, final version accepted September 12, 2019.

Address for correspondence: Khaldoon Alaswad, MD, Henry Ford Health System, Cardiac Catheterization Laboratory, 2799 West Grand Blvd K2, Detroit, MI 48202. Email: kalaswa1@hfhs.org