INTRODUCTION
Severe coronary artery calcifications occur in about 10% of patients undergoing percutaneous coronary intervention (PCI). They constitute a strong independent predictor of adverse cardiovascular events [1]. Even though the risk factors and pathomechanisms leading to severe coronary calcification are well understood, options for effective treatment remain insufficient [2, 3].
In the presence of severe calcification, standard PCI has inferior immediate and long-term outcomes [4–6]. In this situation, advanced lesion modification techniques are indispensable to improve PCI outcomes. Dedicated balloons and ablative techniques are available. Rotational atherectomy (RA) is the oldest and best-recognized ablative technique [7–9]. It is generally acknowledged that superficial modification of calcified atherosclerotic lesions is the optimal mechanism of action in RA. Orbital atherectomy (OA) is the second ablative technique that applies the same procedural approach, albeit using a different device. OA was first introduced into clinical practice about 10 years ago in the US. Currently, in the US the number of interventions using OA and RA is comparable [10, 11]. For a few years, OA has been implemented in Europe; the first procedure in Poland was performed in December 2021. The potential advantages of OA over RA include the ability to ablate calcifications both when the device is moved forward (anterograde) and backward (retrograde) (thus eliminating the risk of coronal entrapment within the lesion), lesser impact on circulatory hemodynamics (no drop in pressure during ablation, particularly beneficial in the case of hemodynamically unstable patients), more efficient ablation of calcifications, and lesser risk of microvascular obstruction during and after the procedure. On the other hand, some data indicate a higher rate of dissections and perforations with OA [12]. In the present study, we present data on first interventions with OA with the aim of showing the immediate safety and efficacy of the procedure.
MATERIALS
The study included 25 consecutive patients who underwent coronary interventions with OA at referral cardiology centers in Białystok, Kraków, and Zabrze between December 2021 and June 2022. The primary inclusion criterion was the presence of de novo stenosis ≥80% with severe calcification in a vessel of 2.5–4.0-mm diameter on angiography.
All the interventions were performed as elective procedures with OA as a primary approach. All stages of interventional treatment, including antiplatelet and perioperative therapy, were standard and remained in concordance with guidelines. Intravascular imaging was broadly recommended before the intervention and to assess the procedure’s outcomes. A 1.25-mm ablative device (crown) was used at two standard speeds of 80 000 and 120 000 rpm, depending on the arterial anatomy and calcification pattern. Higher speed and slower coronal movement within the artery allowed for a greater degree of calcific modification. In OA, effective action is possible while pushing on the stenosis and withdrawing the device through the stenosis. Movement along the vessel was performed in a uniform motion at the recommended speed of about 1–3 mm/s.
After ablation, non-compliant balloon inflation was a routine, scoring/cutting balloons, if necessary, were followed by implantation of the drug-eluting stents. Procedural success was defined as completing lesion modification with OA with subsequent stent placement. Evaluation of the intervention (occurrence of major adverse cardiovascular events) was performed in the perioperative period.
RESULTS AND DISCUSSION
The basic characteristics of patients and treatment data are shown in Table 1.
|
Baseline characteristics (n = 25) |
|
|
Age, years, median (IQR) |
71 (68.5–72.5) |
|
Male sex, n (%) |
23 (92) |
|
EuroSCORE II, median (IQR) |
2.4 (1.5–4) |
|
BMI, kg/m2, median (IQR) |
27.8 (27–32.3) |
|
LVEF, %, median (IQR) |
54 (43–60) |
|
Previous PCI, n (%) |
17 (68) |
|
Previous CABG, n (%) |
9 (36) |
|
Previous ACS, n (%) |
8 (32) |
|
Previous stroke, n (%) |
3 (12) |
|
Atrial fibrillation, n (%) |
10 (40) |
|
Diabetes mellitus, n (%) |
10 (40) |
|
Chronic kidney disease, n (%) |
6 (24) |
|
Peripheral artery disease, n (%) |
8 (32) |
|
Angiographic details |
|
|
SYNTAX I, median (IQR) |
28 (23–33) |
|
SYTNAX II CABG, median (IQR) |
31 (28.5–44)/35.9 (28.8–50.8) |
|
SYTNAX II PCI, median (IQR) |
|
|
Single vessel CCS, n (%) |
3 (12) |
|
Multivessel CCS, n (%) |
14 (56) |
|
Chronic total occlusion, n (%) |
(3) 12 |
|
Procedural details |
|
|
Procedural success, n (%) |
25 (100) |
|
Radial access, n (%) |
24 (95) |
|
Treated artery |
|
|
Left main, n (%) |
6 (24) |
|
Left anterior descending artery, n (%) |
12 (48) |
|
Circumflex artery, n (%) |
3 (12) |
|
Right coronary artery, n (%) |
4 (16) |
|
PCI in CTO, n (%) |
3 (12) |
|
PCI in bifurcation, n (%) |
4 (16) |
|
IVUS, n (%) |
21 (84) |
|
OCT, n (%) |
4 (16) |
|
Scoring balloon, n (%) |
2 (8) |
|
Cutting balloon, n (%) |
1 (4) |
|
Length of all stents, mm, median (IQR) |
49 (30–66) |
|
Average diameter of all stents, mm, median (IQR) |
3.5 (3–3.5) |
|
Total procedure time, min, median (IQR) |
90 (80–105) |
|
Total fluoroscopy time, min, median (IQR) |
25.6 (18.7–32) |
|
K, mGy, median (IQR) |
1029 (679–1538) |
|
Contrast volume, ml, median (IQR) |
170 (150–230) |
|
TIMI 3 score post-procedure, n (%) |
24 (96) |
|
Acetylsalicylic acid prescribed at discharge, n (%) |
25 (100) |
|
Clopidogrel prescribed at discharge, n (%) |
25 (100) |
|
Postprocedural complications |
|
|
Slow flow, n (%) |
2 (8) |
|
No flow, n (%) |
0 (0) |
|
Coronary perforation, n (%) |
0 (0) |
|
Tamponade, n (%) |
0 (0) |
|
Atrioventricular block, n (%) |
2 (8) |
|
Acute kidney injury, n (%) |
0 (0) |
|
Vascular complications of PCI, n (%) |
2 (8) |
|
IVa myocardial infarction, n (%) |
1 (4) |
|
In hospital MACE, n (%) |
1 (4) |
All patients qualified for OA had complex atherosclerotic coronary lesions, and the median SYNTAX Score was 28 (23–33). The presence of severe calcifications was demonstrated in all patients on coronary angiography and/or intracoronary imaging. In line with the current guidelines, in such cases the application of modification methods (RA, OA, or lithotripsy) is advised [13]. Radial access was used in 24 patients (96%); it allowed for minimizing the risk of vascular complications, reducing hospitalization time, and maintaining comparable procedural efficacy as in femoral access. There was a 100% success rate of OA. All patients received DES optimally implanted, with an average length of 49 (30–66) mm, and full TIMI3 (Thrombolytics in Myocardial Infarction) flow in 24 patients (96%).
In comparison with more widely used RA, OA seems to have a couple of differences. In the authors’ subjective opinion, compared to RotaWire, the OA ViperWire Advance® guidewire allows for superior deliverability and maneuverability. In most cases, the guidewire can be delivered directly without a microcatheter and as a result of its larger diameter, subsequent steps of intervention can be done easily with a single guidewire. Presumably, OA can modify the calcified plaque to a greater extent by creating longer and deeper incisions. Finally, the plaque microparticles generated during OA are smaller than in RA (2 μm vs. 5 μm) [14]. Assuming their easier elimination from the microcirculation, this may translate into a lower frequency of coronary flow disturbances. Currently, no data support the above differences as clinically significant [15]. In our study, only one patient showed transient flow impairment, and the criteria for the diagnosis of IVa infarction were met in the postoperative period. It was the PCI with OA in the dominant right coronary artery with retrograde circulation to the left coronary artery, in a patient with a history of CABG with nonfunctioning venous bypasses. Fortunately, the patient was discharged in good condition after several additional days of hospitalization. Additionally, in two patients temporary conduction disturbances not necessitating electrostimulation were observed, in another two cases, minor forearm hematomas occurred not requiring surgical intervention.
A selection of a strategy and evaluation of the treatment for patients with severe coronary artery calcification is challenging. The clinical characteristics of patients and the complexity of atherosclerotic lesions undergoing PCI clearly predefine high cardiovascular risk. In addition, advanced and elaborated PCI techniques increase the risk of adverse events in the perioperative period. In this report, the prevalence of adverse events was low and comparable to the data from large registries [10, 11]. It should be emphasized that most complications during OA or RA procedures are the direct consequence of patients’ high clinical burden and the complexity of the lesions treated. In such difficult cases, ablative methods very often are the sole treatment option. They are used not to generate complications but to overcome them and ensure optimal and effective treatment of patients. Currently, the ECLIPSE trial is recruiting patients to evaluate treatment strategies for severe coronary artery calcification by randomizing patients to OA or conventional angioplasty with implantation of DES stents [15]. The results of this trial will certainly provide important information for the application of OA.
In conclusion, in the analyzed group of patients, the OA procedure turned out to be effective and safe for modifying massively calcified coronary artery lesions. This procedure has a low and acceptable rate of adverse events. Further study in a large group of patients is needed to fully evaluate the procedure and to define indications for its use. At present, the indications for OA overlap with those of the more widely used RA.
Article information
Conflict of interest: None declared.
Funding: None.
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