Thrombocytopenia is often regarded as a risk factor for bleeding complications in patients undergoing percutaneous coronary intervention (PCI). The risk of mild to moderate baseline and acquired thrombocytopenia on bleeding and thrombotic or thromboembolic complications in patients with atrial fibrillation on oral anticoagulation therapy undergoing PCI, however, remains largely unknown. Management of Patients With Atrial Fibrillation undergoing Coronary Artery Stenting is a multicenter European prospective registry enrolling patients with atrial fibrillation undergoing PCI. We assessed the rate of bleeding complications as defined by Bleeding Academic Research Consortium and a composite of major adverse cardiac and cerebrovascular events (MACCE) including all-cause mortality, myocardial infarction, transient ischemic attack or stroke, stent thrombosis, systemic arterial embolism, or revascularization; and a composite of any harmful event (Bleeding Academic Research Consortium and MACCE) at 12-month follow-up in 861 consecutive patients undergoing PCI. Patients were divided into those with mild to moderate baseline thrombocytopenia (platelet count <150 × 10 9 /L; n = 99) and control group (platelet count >150 × 10 9 /L; n = 762). At hospital discharge, thrombocytopenia had no effect on prescribed antithrombotic treatment, and triple therapy (vitamin K antagonist + aspirin + clopidogrel) was the most common combination in both patient groups (69% vs 73%, p = 0.40). No differences in all-cause mortality (12% vs 11%, p = 0.79), MACCE (23% vs 22%, p = 0.87), or bleeding complications (23% vs 19%, p = 0.26) were detected. Acquired in-hospital thrombocytopenia occurred in 9.7% of patients, and it was associated with similar risk of adverse outcomes compared with control group. In conclusion, mild to moderate baseline thrombocytopenia does not seem to have a clinically significant effect on bleeding or thrombotic or thromboembolic complications after PCI in these frail patients receiving multiple antithrombotic drugs.
About 5% to 8% of patients referred for percutaneous coronary intervention (PCI) have an indication for long-term anticoagulation (AC), mainly because of atrial fibrillation (AF). Baseline and acquired thrombocytopenia and decrease in platelet count after the procedure are often regarded as risk factors for bleeding complications after PCI. However, it is not known whether periprocedural mild to moderate thrombocytopenia (platelet count <150 × 10 9 /L) affects the use of antithrombotic treatment in patients with AF on oral AC with vitamin K antagonists (VKA). Moreover, the effect of mild to moderate thrombocytopenia and acquired thrombocytopenia on mortality and bleeding risk remains largely unknown in this frail patient population. In this 12-month prospective follow-up registry, we sought to compare antithrombotic treatment strategies, all-cause mortality, a composite of major adverse cardiac and cerebrovascular events (MACCE), and bleeding complications in patients with AF undergoing PCI.
Methods
Management of Patients With Atrial Fibrillation Undergoing Coronary Artery Stenting (AFCAS) is an observational, multicenter, prospective registry including patients with AF who are referred for PCI ( http://Clinicaltrials.gov identifier NCT00596570 ). Inclusion criteria included (1) history of AF (paroxysmal, persistent, or permanent) or (2) ongoing AF during the target hospital stay, in patients undergoing PCI. Because of the observational design, the only exclusion criterion was unwillingness or inability to participate in the study or to give written informed consent. At each participating center, patients were treated according to local policies and were followed up for 12 months (telephonic interview at 3, 6, and 12 months). Ethical committees of participating centers approved the study protocol, and written informed consent was obtained from every patient. The study complied with the Declaration of Helsinki.
Coronary angiography and PCI were performed using either radial or femoral approach for arterial access, and the hemostasis was obtained according to the local practice. Lesions were treated according to the contemporary interventional techniques. Low-molecular-weight heparin (enoxaparin sodium and dalteparin), unfractionated heparin, bivalirudin, and glycoprotein IIb/IIIa inhibitors were administered entirely up to the operator’s discretion.
The end points were (1) all-cause mortality, (2) a composite of MACCE including all-cause mortality, myocardial infarction, repeat revascularization, stent thrombosis, transient ischemic attack (TIA), stroke, other arterial embolism, and venous embolism, (3) bleeding complications, and (4) any harmful event (MACCE and bleeding complications) during the 12-month follow-up period. Periprocedural myocardial infarction was not routinely screened, but if suspected, a troponin level >3× normal ninety-ninth percentile level was required for the diagnosis. For the diagnosis of myocardial reinfarction, a new increase of >50% above the baseline injury marker level was required. Revascularization was defined as PCI or coronary bypass in any vessel excluding those planned and scheduled at the time of the index procedure. Stent thrombosis was defined according to Academic Research Consortium classification as definite and probable. TIA was defined as a focal transient (<24 hours) neurologic deficit adjudicated by a neurologist. Stroke as a permanent focal neurologic deficit adjudicated by a neurologist and confirmed by computed tomography or magnetic resonance imaging. Systemic embolism was defined as signs and symptoms of peripheral ischemia associated with a positive imaging test result.
Bleeding complications were defined according to the Bleeding Academic Research Consortium (BARC) criteria as minor (BARC 2) and major (BARC 3a, 3b, 3c, and 5).
Thrombocytopenia was defined as a platelet count below the reference lower limit of normal (150 × 10 9 /L). In subsequent analysis, patients were further divided into those with mild (100 to 149 × 10 9 /L) or moderate to severe (<100 × 10 9 /L) thrombocytopenia. Acquired thrombocytopenia was defined as a decrease of platelet levels from normal baseline count (>150 × 10 9 /L) to thrombocytopenic level (<150 × 10 9 /L) during in-hospital phase or >50% decrease in platelet count from preintervention platelet count or both.
Continuous variables are reported as mean ± SD, skewed variables as median and interquartile range, and categorical variables as percentage. Student’s t test, Mann-Whitney U test, and chi-square test were used for comparison of continuous, skewed, and categorical variables, respectively. A propensity score was calculated to estimate the risk of being included in the thrombocytopenia, acquired thrombocytopenia, or control group. This was performed by including in logistic regression those variables with p <0.2 in univariate analysis and using a backward procedure. The discriminatory ability of the estimated propensity score was evaluated by receiver operating characteristics curve analysis. Survival analysis was performed using Kaplan-Meier’s method and Cox proportional hazards method. A p value <0.05 was considered statistically significant. All computations were carried out with SPSS software (V16.0, SPSS Inc., Chicago, Illinois).
Results
Altogether 929 patients with AF were prospectively enrolled and followed for 12 months after the index procedure. Periprocedural platelet count was available in 861 patients (93%). Mild to moderate thrombocytopenia (platelet count 80 to 150/μl) was detected in 99 (11%, thrombocytopenia group) and platelet count >150 × 10 9 /L in 762 (89%) of the patients (control group). Baseline and periprocedural characteristics of the study population are listed in Tables 1 and 2 .
| Variable | Thrombocytopenia (n = 99) | Control (n = 762) | p |
|---|---|---|---|
| Age (yrs) | 74 ± 8.0 | 73 ± 8.1 | 0.38 |
| Men | 84 (85) | 518 (68) | <0.001 |
| CHADS 2 score | 2.0 ± 1.3 | 2.3 ± 1.2 | 0.12 |
| CHADS 2 score ≥2 | 67 (68) | 540 (71) | 0.56 |
| International normalized ratio (preprocedural) | 2.0 ± 0.6 | 1.9 ± 0.7 | 0.61 |
| Diabetes mellitus | 31 (31) | 278 (37) | 0.37 |
| Hypercholesterolemia | 68 (69) | 502 (66) | 0.65 |
| Current or ex-smoker | 6 (6) | 82 (11) | 0.16 |
| Hypertension | 75 (76) | 649 (85) | 0.02 |
| Paroxysmal AF | 27 (27) | 305 (40) | 0.02 |
| Persistent AF | 9 (9) | 94 (12) | 0.51 |
| Permanent AF | 63 (64) | 360 (47) | 0.003 |
| History of peptic ulcer | 6 (6) | 38 (5) | 0.63 |
| History of cerebral hemorrhage | 2 (2) | 8 (1) | 0.32 |
| History of GI hemorrhage | 3 (3) | 18 (2) | 0.73 |
| Heart failure | 21 (21) | 161 (21) | 1.0 |
| Previous TIA | 5 (5) | 37 (5) | 0.80 |
| Previous stroke | 7 (7) | 95 (13) | 0.14 |
| Previous MI | 35 (35) | 186 (24) | 0.03 |
| Previous PCI | 23 (23) | 124 (16) | 0.09 |
| Previous coronary bypass | 17 (17) | 108 (14) | 0.45 |
| Indication for PCI | |||
| Stable angina pectoris | 39 (39) | 332 (44) | 0.45 |
| Unstable angina pectoris | 27 (27) | 133 (18) | 0.03 |
| NSTEMI | 21 (21) | 193 (25) | 0.46 |
| STEMI | 12 (12) | 103 (14) | 0.88 |
| Variable | Thrombocytopenia (n = 99) | Control (n = 762) | p |
|---|---|---|---|
| Femoral sheath | 75 (76) | 556 (73) | 0.63 |
| Treated coronary vessels | 1.1 ± 0.4 | 1.2 ± 0.4 | 0.40 |
| Patients with drug-eluting stents | 24 (24) | 189 (25) | 1.0 |
| Stent diameter (mm) | 3.1 ± 0.4 | 3.1 ± 0.5 | 0.32 |
| Total stent length (mm) | 27 ± 17 | 25 ± 16 | 0.31 |
| Balloon angioplasty | 1 (1) | 28 (4) | 0.25 |
| Procedural success | 94 (95) | 741 (97) | 0.11 |
| Hemostasis | |||
| Manual compression | 38 (38) | 321 (42) | 0.85 |
| Compression device ∗ | 27 (27) | 178 (23) | 0.65 |
| Access-site closure device † | 37 (37) | 261 (34) | 0.80 |
∗ FemoStop, pneumatic compression device (Radi medical system, Sweden).
† Angioseal, closure device (St. Jude medical, United States).
At hospital discharge, triple therapy with VKA, aspirin, and clopidogrel was prescribed to 68 (69%) versus 555 (73%, p = 0.40); dual antiplatelet therapy with aspirin and clopidogrel (or prasugrel, n = 1) to 16 (16%) versus 142 (19%, p = 0.68); VKA + clopidogrel to 12 (12%) versus 54 (7.1%, p = 0.10); and VKA + aspirin to 3 (3.0%) versus 11 (1.4%, p = 0.21) of patients in thrombocytopenia and control group, respectively. No significant differences in the duration of clopidogrel treatment were observed between patients in thrombocytopenia and control group ( Figure 1 ) except for patients receiving VKA and clopidogrel in whom the duration of clopidogrel treatment was limited to 1 to 3 months in patients with thrombocytopenia whereas the median was 9 months in control group (p = 0.06; Figure 1 , Table 3 ). The dosage of aspirin was 100 mg/day in 97% versus 95% (p = 1.0) and 50 mg/day in 3.5% versus 3.9% (p = 1.0) of patients in the thrombocytopenia and controls groups, respectively.
| Duration of Therapy | Thrombocytopenia, n = 99 (%) | Control, n = 759 (%) |
|---|---|---|
| Aspirin | Lifelong: 57 (58) | Lifelong: 483 (64) |
| 12 months: 11 (11) | 12 months: 74 (10) | |
| 6 months: 1 (1) | 6 months: 11 (1) | |
| 1 month: 13 (13) | 1 month: 89 (12) | |
| No aspirin: 15 (15) | No aspirin: 73 (10) | |
| Clopidogrel ∗ | Lifelong: 4 (4) | Lifelong: 21 (3) |
| 12 months: 22 (22) | 12 months: 220 (29) | |
| 6 months: 9 (9) | 6 months: 55 (7) | |
| 1 month: 40 (40) | 1 month: 295 (39) | |
| No clopidogrel: 4 (4) | No clopidogrel: 29 (4) | |
| VKA/LMWH † | Lifelong: 66 (67) | Lifelong: 479 (63) |
| 1–12 months: 1 (1) | 1–12 months: 11 (1) | |
| 1 month: 13 (13) | 1 month: 13 (2) | |
| No VKA: 20 (19) | No VKA: 259 (34) |
† VKA/LMWH refers to use of either of the drugs at discharge (temporary LMWH when using bridging therapy).
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