**2. Immediate and long-term outcomes of ECMO support for complex high-risk PCI in stable angina patients: A single-center experience**

Elective high-risk PCI with ECMO support in **stable angina** patients with the multivessel disease will be presented in this section. These data are based on the in-hospital and 12-month outcomes of a single-center retrospective observational study in the small series of 16 patients. The purpose of the study was to evaluate the incidence of MACCE (a composite of all-cause death, myocardial infarction (MI), stroke and target vessel revascularization) at 30 days and 12 months. Additionally, bleeding and complete revascularization rates were evaluated. Complete revascularization was defined as the PCI procedure, as a result of which the residual SYNTAX score was ≤2. For the classification of bleeding, the definition of Bleeding Academic Research Consortium (BARC) was used [22]. Hemorrhagic complications of type 3 and higher were taken into account.

High-risk PCI was defined as having two of the three parameters [20]: (1) ejection fraction <35%; (2) Jeopardy Score ≥ 8 [2]; (3) intervention for bifurcation and/or left main and/or chronic total occlusion. An indication for high-risk PCI with ECMO support was based on the heart team decision for those patients, who were not suitable for some types of revascularization (CABG or PCI) and who had two of the three parameters of high-risk PCI.

We started ECMO prior to PCI and used the "RotaFlow System" (by MAQUET). The ECMO cannula was inserted using a surgical technique (9 (56.2%)) and endovascular approach (ProStar XL, 7 (45.8%)). The mean ECMO time was 2.4–3.2 L/min/m<sup>2</sup> (70–100% from the estimated).

The medications during PCI included unfractionated heparin and acetylsalicylic acid. All of the patients received the loading dose of clopidogrel before PCI. Aspirin was prescribed before revascularization (75 mg once daily) for all the study patients and it was continued indefinitely. Unfractionated heparin was used (IV bolus of 100 IU per kilogram of body weight followed by an adjustment according to the target activated clotting time of 250–300 seconds). Antiplatelet regimen routinely included clopidogrel (a loading dose of 300 mg at the time of PCI unless used in advance; then 75 mg daily, the recommended duration of treatment was 12 months).

Baseline clinical and angiographic characteristics of the study patients are shown in **Table 1**. Of note, the mean age was 62.8 ± 6.5 years, and the majority of patients were males (81.2%). Diabetes mellitus was present in 18.7, 75% had a history of myocardial infarction, peripheral artery disease was observed in 50% of patients. Left ventricular ejection fraction (LVEF) was poor: 37.9 ± 17.5%. Our patients had stenotic lesions of two or more significant epicardial arteries and/or large branches (≥2.5 mm) ≥70% and/or stenosis of LMCA ≥50%. The target vessel for PCI was determined taking into account the data on the viability of the myocardium on cardiac magnetic resonance imaging. Fifteen (93.7%) patients had 3 or more affected vessels, significant LMCA stenosis was diagnosed in 7 (43.7%) patients and mean SYNTAX score was 31.4 ± 9.8. In general, stable CAD patients (n = 16) were characterized by a high incidence of a prior MI, very low ejection fraction and severe multivessel disease involving LMCA.

of the patient with carotid artery disease. A BARC bleeding of type 3 or more was observed in 6 (37.5%) patients. The mean hospital stay was 12.6 ± 4.8 days. A significant decrease in hemoglobin levels required blood transfusion in six cases. The blood use averaged 4.2 units

BARC: Bleeding Academic Research Consortium, COPD: chronic obstructive pulmonary disease, CCS: Canadian

**Variables Stable CAD patients**

Mean age 62.8 ± 6.5 (51–75) Male 13 (81.2%) Mean left ventricular ejection fraction 37.9 ± 17.5 Left ventricular ejection fraction <35 11 (68.7%) EuroScore II 3.2 ± 2.4 CCS II 6 (37.5%) CCS III-IV 10 (62.5%) Chronic kidney disease 4 (25%) COPD 2 (12.5%) Diabetes mellitus 3 (18.7%) Prior myocardial infarction 12 (75%) Arterial hypertension 134 (89.3%) Peripheral artery disease 8 (50%) Prior stroke 1 (6.2%) SYNTAX Score 31.4 ± 9.8 Jeopardy score [2] 11.3 ± 0.9 Affected vessels: 1, 2 1 (6.2%) Affected vessels: ≥3 15 (93.7%) LMCA stenosis ≥50% 7 (43.7%)

**PCI+ ECMO (n = 16)**

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39

Long-Term Outcome of High-Risk Percutaneous Coronary Interventions with Extracorporeal…

Long-term outcomes of the study are presented in **Table 2**. About 25% mortality rate was observed at 12 months. The combined endpoint (all-cause death, myocardial infarction (MI), stroke and target vessel revascularization) was observed in 4 (25%) patients. Three (18.7%) deaths occurred in the post-hospitalization period as a result of acute myocardial infarction. Two were due to acute stent thrombosis and one as a consequence of stent restenosis. Myocardial infarctions in the long-term follow-up period (3 (18.7%)) were predominantly new cases after the hospital discharge and led to TVR in two patients. There were no addi-

of red blood cells.

tional stroke cases in the follow-up period.

Cardiovascular Society grading of angina pectoris.

**Table 1.** Baseline characteristics of the study population.

We successfully performed all PCI + ECMO interventions. Procedural characteristics and in-hospital outcomes of the study patients are shown in **Table 2**. The mean bypass/PCI duration was 115.6 ± 43.7/98.6 ± 31.1 minutes. All of the patients were weaned from the system immediately after PCI directly in the cath-lab. Only six (37.5%) patients had a complete revascularization while the mean number/length of implanted stents was 3.6 ± 1.2 and 75.8 ± 23.4 mm, respectively. Only second-generation drug-eluting stents (DES) were implanted. There was one stroke case (6.2%) 5 days after PCI + ECMO which led to the death


BARC: Bleeding Academic Research Consortium, COPD: chronic obstructive pulmonary disease, CCS: Canadian Cardiovascular Society grading of angina pectoris.

**Table 1.** Baseline characteristics of the study population.

and 12 months. Additionally, bleeding and complete revascularization rates were evaluated. Complete revascularization was defined as the PCI procedure, as a result of which the residual SYNTAX score was ≤2. For the classification of bleeding, the definition of Bleeding Academic Research Consortium (BARC) was used [22]. Hemorrhagic complications of type 3

High-risk PCI was defined as having two of the three parameters [20]: (1) ejection fraction <35%; (2) Jeopardy Score ≥ 8 [2]; (3) intervention for bifurcation and/or left main and/or chronic total occlusion. An indication for high-risk PCI with ECMO support was based on the heart team decision for those patients, who were not suitable for some types of revasculariza-

We started ECMO prior to PCI and used the "RotaFlow System" (by MAQUET). The ECMO cannula was inserted using a surgical technique (9 (56.2%)) and endovascular approach

The medications during PCI included unfractionated heparin and acetylsalicylic acid. All of the patients received the loading dose of clopidogrel before PCI. Aspirin was prescribed before revascularization (75 mg once daily) for all the study patients and it was continued indefinitely. Unfractionated heparin was used (IV bolus of 100 IU per kilogram of body weight followed by an adjustment according to the target activated clotting time of 250–300 seconds). Antiplatelet regimen routinely included clopidogrel (a loading dose of 300 mg at the time of PCI unless used in advance; then 75 mg daily, the recommended duration of treatment was

Baseline clinical and angiographic characteristics of the study patients are shown in **Table 1**. Of note, the mean age was 62.8 ± 6.5 years, and the majority of patients were males (81.2%). Diabetes mellitus was present in 18.7, 75% had a history of myocardial infarction, peripheral artery disease was observed in 50% of patients. Left ventricular ejection fraction (LVEF) was poor: 37.9 ± 17.5%. Our patients had stenotic lesions of two or more significant epicardial arteries and/or large branches (≥2.5 mm) ≥70% and/or stenosis of LMCA ≥50%. The target vessel for PCI was determined taking into account the data on the viability of the myocardium on cardiac magnetic resonance imaging. Fifteen (93.7%) patients had 3 or more affected vessels, significant LMCA stenosis was diagnosed in 7 (43.7%) patients and mean SYNTAX score was 31.4 ± 9.8. In general, stable CAD patients (n = 16) were characterized by a high incidence of a prior MI, very low ejection fraction

We successfully performed all PCI + ECMO interventions. Procedural characteristics and in-hospital outcomes of the study patients are shown in **Table 2**. The mean bypass/PCI duration was 115.6 ± 43.7/98.6 ± 31.1 minutes. All of the patients were weaned from the system immediately after PCI directly in the cath-lab. Only six (37.5%) patients had a complete revascularization while the mean number/length of implanted stents was 3.6 ± 1.2 and 75.8 ± 23.4 mm, respectively. Only second-generation drug-eluting stents (DES) were implanted. There was one stroke case (6.2%) 5 days after PCI + ECMO which led to the death

(70–100% from the

tion (CABG or PCI) and who had two of the three parameters of high-risk PCI.

(ProStar XL, 7 (45.8%)). The mean ECMO time was 2.4–3.2 L/min/m<sup>2</sup>

and severe multivessel disease involving LMCA.

and higher were taken into account.

38 Advances in Extra-corporeal Perfusion Therapies

estimated).

12 months).

of the patient with carotid artery disease. A BARC bleeding of type 3 or more was observed in 6 (37.5%) patients. The mean hospital stay was 12.6 ± 4.8 days. A significant decrease in hemoglobin levels required blood transfusion in six cases. The blood use averaged 4.2 units of red blood cells.

Long-term outcomes of the study are presented in **Table 2**. About 25% mortality rate was observed at 12 months. The combined endpoint (all-cause death, myocardial infarction (MI), stroke and target vessel revascularization) was observed in 4 (25%) patients. Three (18.7%) deaths occurred in the post-hospitalization period as a result of acute myocardial infarction. Two were due to acute stent thrombosis and one as a consequence of stent restenosis. Myocardial infarctions in the long-term follow-up period (3 (18.7%)) were predominantly new cases after the hospital discharge and led to TVR in two patients. There were no additional stroke cases in the follow-up period.


bleeding and blood transfusions. At the 12-month follow-up, the results became less encouraging. A high number of myocardial infarctions in combination with an in-hospital stroke led to an increased number of cumulative adverse outcomes of 25%. The attention should be drawn to the unsatisfactory effect of implantation of second-generation DES (myocardial infarction and death from myocardial infarction in 18.7% of patients). Nevertheless, our data do not go beyond the results presented in the literature. The long-term all-cause mortality in ischemic cardiomyopathy patients with reduced ejection fraction increased up to 58.9 and 66.1% in the CABG and guideline-directed medical therapy groups, respectively [23, 24]. The main limitation of our analysis is a small number of patients. Therefore, in order to answer the question on the role of ECMO for high-risk PCI in chronic CAD patients, larger trials are

Long-Term Outcome of High-Risk Percutaneous Coronary Interventions with Extracorporeal…

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41

In conclusion, our study was designed to report the unique single-center experience in using ECMO to manage high-risk **stable angina** patients in the catheterization laboratory. In-hospital results suggest that PCI with ECMO can be successfully performed and may be a feasible strategy of revascularization in a high-risk cohort of chronic CAD patients with adverse outcomes after any type of revascularization (CABG and PCI). Bleeding control is a critical aspect of care during the PCI + ECMO procedure. The long-term results of PCI with the support of artificial circulation require additional evaluation in larger or/and randomized studies. Particular attention should be paid to factors that increase the risk of stent thrombosis (the number of stents, the quality of stents, the procedure for stent implantation, antiplatelet

**3. PCI + ECMO vs. CABG for NSTE-ACS patients with multivessel** 

We followed NSTE-ACS multivessel coronary artery disease (MVCAD) patients consecutively admitted to our hospital from 2012 to 2015 and undergone revascularization with highrisk PCI + ECMO support or CABG. The study included 53 patients (PCI + ECMO, n = 23, and CABG, n = 30). It was a single-center registry, which compared 12-month outcomes. Inclusion criteria were significant multivessel coronary disease and/or stenosis of the left main coronary artery (LMCA) ≥50%. The PCI + ECMO group of NSTE-ACS patients had an intermediate risk of adverse cardiovascular outcomes (mean GRACE score 117.3 ± 19.4, mean EuroScore II 4.3 ± 3.9%), and a high SYNTAX Score: 33.3 ± 8.3. Significant LMCA stenosis was diagnosed in 60.7% of patients. Every third patient had diabetes mellitus, a prior myocardial infarction was observed in 56.4% cases, peripheral artery disease was diagnosed in 60.7% of patients of the study population. High-risk PCI was defined as having two of the three parameters: (1) left ventricular ejection fraction less than 35%; (2) a large amount of myocardium at risk (Jeopardy Score 8 and more [2]) and (3) complex PCI. An indication for high-risk PCI with ECMO support was based on the heart team decision for those patients, who were not suitable for some types of revascularization (CABG or PCI) and who had two of the three param-

required.

therapy).

**disease**

eters of high-risk PCI.

BARC: Bleeding Academic Research Consortium, MI: myocardial infarction, TVR: target vessel revascularization.

**Table 2.** Procedural characteristics and study end points.

This study had patients at high risk of adverse events for any type of revascularization (CABG and PCI). This is the largest series of consecutive high CABG risk chronic CAD patients who underwent ECMO in the elective pre-procedural manner. The main hypothesis of the study was that PCI + ECMO may be a feasible strategy of revascularization for **stable angina** patients at a high risk for CABG or PCI only.

All the patients had severe multivessel disease involving LMCA, poor left ventricular fraction as a result of a prior MI and underwent challenging PCI with ECMO support as an adjunct modality in the elective pre-procedural setting, which allowed to complete a successful revascularization without hemodynamic disturbances and to wean from ECMO immediately after PCI. The hospital results looked satisfactory. There were no serious cardiac adverse outcomes. Hemorrhagic complications were not fatal, although it is necessary to note a high incidence of bleeding and blood transfusions. At the 12-month follow-up, the results became less encouraging. A high number of myocardial infarctions in combination with an in-hospital stroke led to an increased number of cumulative adverse outcomes of 25%. The attention should be drawn to the unsatisfactory effect of implantation of second-generation DES (myocardial infarction and death from myocardial infarction in 18.7% of patients). Nevertheless, our data do not go beyond the results presented in the literature. The long-term all-cause mortality in ischemic cardiomyopathy patients with reduced ejection fraction increased up to 58.9 and 66.1% in the CABG and guideline-directed medical therapy groups, respectively [23, 24]. The main limitation of our analysis is a small number of patients. Therefore, in order to answer the question on the role of ECMO for high-risk PCI in chronic CAD patients, larger trials are required.

In conclusion, our study was designed to report the unique single-center experience in using ECMO to manage high-risk **stable angina** patients in the catheterization laboratory. In-hospital results suggest that PCI with ECMO can be successfully performed and may be a feasible strategy of revascularization in a high-risk cohort of chronic CAD patients with adverse outcomes after any type of revascularization (CABG and PCI). Bleeding control is a critical aspect of care during the PCI + ECMO procedure. The long-term results of PCI with the support of artificial circulation require additional evaluation in larger or/and randomized studies. Particular attention should be paid to factors that increase the risk of stent thrombosis (the number of stents, the quality of stents, the procedure for stent implantation, antiplatelet therapy).
