CATHARSIS
Final Results of Cilostazol-Aspirin Therapy against Recurrent Stroke with Intracranial Artery Stenosis
Clinical Question
Does cilostazol plus aspirin reduce progression of intracranial artery stenosis and vascular events more than aspirin alone in patients with symptomatic intracranial artery stenosis?
Study Overview
Objective
Cilostazol plus aspirin versus aspirin alone in preventing progression of intracranial artery stenosis (IAS) and recurrent vascular events.
Study Summary
Cilostazol plus aspirin did not significantly reduce IAS progression compared to aspirin alone, but exploratory analyses suggested a lower risk of composite vascular and silent infarct outcomes in the combination group. 165 randomized; 163 in ITT (CA n=83, A n=80).
Intervention
Cilostazol 200 mg/day + aspirin 100 mg/day vs. aspirin 100 mg/day alone. Patients were treated and followed for 2 years.
Bottom Line
Cilostazol 200 mg/day + aspirin 100 mg/day did not significantly reduce intracranial artery stenosis (IAS) progression vs aspirin alone (9.6% vs 5.6%; P=0.53) over 2 years. IAS progression was far lower than expected in both arms (~6–10% vs predicted 35–60%), likely due to aggressive risk-factor control. Exploratory logistic regression showed significant reduction in composite vascular events + silent infarcts (OR 0.37, 95% CI 0.14–0.97; P=0.04). 165 randomized (CA n=83, A n=82); 163 ITT (CA n=83, A n=80); 60 Japanese centers.
Major Points
- Primary endpoint NS: IAS progression 9.6% (CA) vs 5.6% (A) at 2 years (P=0.53).
- IAS progression far lower than expected (9.6%/5.6% vs predicted 35–60%) — attributed to aggressive risk-factor control in both arms.
- Vascular events numerically lower: annual rate 3.1% vs 7.4%; adjusted HR 0.39 (95% CI 0.12–1.13); P=0.09, NS.
- Exploratory logistic regression composites significant: all vascular events + silent infarcts OR 0.37 (95% CI 0.14–0.97), P=0.04; stroke + silent infarcts OR 0.34 (95% CI 0.12–0.96), P=0.04; all vascular events + worsening mRS + silent infarcts OR 0.41 (95% CI 0.18–0.92), P=0.03.
- No deaths in either group. Serious hemorrhage 4/83 (CA) vs 3/80 (A); subtypes: CA — GI 2, vitreous 1, hematuria 1; A — SAH 1, cerebral hemorrhage 1, GI 1.
- Underpowered: 163 ITT (planned 200). Event rates far below projected.
- Baseline imbalances favoring risk in CA arm: males 77.1% vs 53.8% (p<0.01), hypertension 83.1% vs 68.8% (p=0.04), diabetes 48.2% vs 25.0% (p<0.01) — biases against CA.
- SBP reduced from 137.4 to 131.1 mm Hg and total cholesterol from 195.4 to 182.9 mg/dL in all patients over 2 years (both p<0.01).
- 163 ITT patients across 60 Japanese centers, open-label, 2-year follow-up.
- Supports rationale for larger CSPS.com trial (n≈4,000) for definitive evidence on cilostazol in IAS.
Design
Study Type: Multicenter, open-label, randomized controlled trial
Randomization: 1
Blinding: Open-label
Enrollment Period: June 2006 – March 2010
Follow-up Duration: 2 years (mean 762 days)
Centers: 60
Countries: Japan
Sample Size: 165
Sample Size (ITT): 163
Analysis: Intention-to-treat
Stratification: Age (≥70 vs <70) and stenosis location (supraclinoid ICA/M1 MCA vs basilar artery)
Inclusion Criteria
- Noncardioembolic ischemic stroke 2 weeks to 6 months prior to entry
- Responsible lesion identified on magnetic resonance imaging (MRI)
- Intracranial artery stenosis >50% on MRA in the supraclinoid internal carotid artery, the M1 portion of the middle cerebral artery, or the basilar artery
- Age 45–85 years
- Able to visit an outpatient clinic
Exclusion Criteria
- Potential cardiac sources of embolism
- History of symptomatic intracranial hemorrhage
- Other hemorrhagic diseases (active peptic ulcer, hemophilia, or coagulation abnormalities)
- Hypersensitivity to cilostazol or aspirin
- Congestive heart failure or uncontrollable angina pectoris
- Thrombocytopenia (<100,000/mm³)
- Liver dysfunction (AST or ALT >100 IU/L)
- Renal dysfunction (creatinine >2.0 mg/dL)
- Inability to be followed up during the study period
- Current use of cilostazol or warfarin
- Inability to undergo MRI
- Scheduled percutaneous transluminal coronary angioplasty or bypass surgery
- Enrollment in other clinical trials
Arms
| Field | CA Group: Cilostazol + Aspirin | Control |
|---|---|---|
| N Randomized | 83 | 82 |
| N ITT | 83 | 80 |
| Intervention | Cilostazol 200 mg/day + Aspirin 100 mg/day | Aspirin 100 mg/day |
| Duration | 2 years | 2 years |
Outcomes
| Outcome | Type | Control | Intervention | HR / OR / RR | P-value |
|---|---|---|---|---|---|
| Progression of intracranial artery stenosis at 2 years (on MRA) | Primary | 5.6% | 9.6% | 0.53 | |
| All vascular events (annual incidence) | Secondary | 7.4% | 3.1% | 0.39 | 0.09 |
| Stroke (annual recurrence) | Secondary | 5.2% | 2.5% | 0.44 | 0.19 |
| Ischemic stroke (annual recurrence) | Secondary | 4.5% | 2.5% | 0.47 | 0.26 |
| New silent brain infarcts | Secondary | 10.0% | 4.8% | 0.24 | |
| Worsening of mRS | Secondary | 18.9% | 10.1% | 0.17 | |
| Major Hemorrhage | Adverse | 3/80 — subarachnoid hemorrhage 1, cerebral hemorrhage 1, GI bleeding 1 | 4/83 — GI bleeding 2, vitreous hemorrhage 1, hematuria 1 | ||
| Death | Adverse | 0 | 0 |
Criticisms
- Small sample size — underpowered to detect differences in the primary endpoint and adjudicated event outcomes.
- Open-label design; potential for ascertainment bias.
- Primary endpoint (IAS progression) not statistically different.
- Composite benefits derive from post-hoc exploratory logistic regression without control for multiple testing.
- Lack of central adjudication for stroke subtype.
- Baseline imbalances (males, HTN, DM higher in CA arm) required covariate adjustment.
- 2-year follow-up may be short for a chronic stenotic vascular disease.
- Japanese-only population may limit generalizability.
Funding
Operational and technical support provided by the Translational Research Informatics Center / Foundation for Biomedical Research and Innovation (FBRI), Kobe, Japan. FBRI is a public interest corporation receiving financial resources from the Japanese government and pharmaceutical companies including Otsuka Pharmaceutical Co., Ltd. (manufacturer of cilostazol). Otsuka had no role in data collection, data analysis, data interpretation, or writing of the report.
Based on: CATHARSIS (Cerebrovascular Diseases Extra, 2015)
Authors: Uchiyama S, Sakai N, Toi S, ..., for the CATHARSIS Study Group
Citation: Uchiyama S, et al. Cerebrovasc Dis Extra 2015;5:1–13.
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