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Cardiovascular, Case 0092 — Antiplatelet Therapy

Aspirin Alone or a Bounded Course of Ticagrelor After His Bypass

One large trial found that adding ticagrelor to aspirin protects his vein grafts. Another, just as large, found it doesn't. A third, newer trial suggests the real answer may be a matter of how long, not whether.

Abbreviations, terms, and other agents mentioned in this case CABG — coronary artery bypass grafting  ·  SVG — saphenous vein graft  ·  LIMA — left internal mammary artery  ·  LAD — left anterior descending artery  ·  DAPT — dual antiplatelet therapy  ·  AF — atrial fibrillation  ·  VTE — venous thromboembolism  ·  P2Y12 — the platelet ADP receptor blocked by clopidogrel, prasugrel, and ticagrelor
Presentation

W.D., a 71-year-old man, spent his career as a railroad conductor and has moved temporarily into his daughter's guest house to recover close to family since his surgery. Ten days ago he underwent coronary artery bypass grafting for three-vessel disease — a left internal mammary artery graft to his LAD and two saphenous vein grafts to the circumflex and right coronary territories — and his recovery so far has been unremarkable, walking the length of his daughter's driveway twice a day as instructed. He has no atrial fibrillation, no mechanical valve, no history of venous thromboembolism, and no other indication for anticoagulation beyond the surgery itself.

Roughly fifteen percent of saphenous vein grafts occlude within the first year after CABG despite standard aspirin therapy, and the question of whether adding a P2Y12 inhibitor improves on that is one the field's largest trials have answered in opposite directions. DACAB, an open-label Chinese trial of 500 patients, found ticagrelor plus aspirin achieved 88.7% one-year graft patency against 76.5% with aspirin alone, a clear absolute difference. POPular CABG enrolled a near-identical 499 patients but was double-blind and placebo-controlled, and found no benefit — occlusion in 10.5% of grafts with added ticagrelor against 9.1% with aspirin alone, numerically the wrong direction and well within the range of chance. A newer and much larger trial, TOP-CABG, reframes the question rather than settling it: in 2,290 patients, three months of ticagrelor-based dual therapy followed by de-escalation to aspirin alone was noninferior to twelve months for graft patency (10.8% versus 11.2% occlusion) and cut clinically relevant bleeding from 13.2% to 8.3%. It carried no aspirin-alone arm, so it cannot say whether intensified therapy beats aspirin at all — only that if it is used, three months appears to be enough.

W.D. · 71 10 Days Post-CABG
History
3-vessel CAD, CABG 10 days ago (LIMA-LAD, 2 SVGs)
Anticoagulation indications
None — no AF, no mechanical valve, no VTE history
Recovery status
Ambulating twice daily, wound healing well
Bleeding risk factors
Age 71, recent major surgery
Renal function
Normal
Current medications
Aspirin 81 mg daily since surgery

At the post-CABG follow-up

Cardiothoracic Surgeon Opening

I'd stay with aspirin alone. POPular CABG is the blinded, placebo-controlled trial of the two — DACAB was open-label at essentially the same sample size — and it found no patency benefit from adding ticagrelor — only added bleeding risk in a 71-year-old ten days out from major surgery.

Interventional Cardiologist Response

DACAB's positive result shouldn't be dismissed just because POPular CABG came out differently — two well-conducted trials disagreeing is a real signal that the answer may depend on something neither trial isolated. TOP-CABG's newer data is what I'd weight most heavily here: three months of ticagrelor-based DAPT held patency equal to a full twelve months while cutting clinically relevant bleeding from 13.2% to 8.3%. It can't tell us the dual therapy beat aspirin alone — there was no aspirin-only arm — but it does tell us that if we intensify, we don't need to do it for a year.

That's not really a compromise position — it's evidence that the whole DACAB-versus-POPular disagreement may have been partly a duration question in disguise, not a real either-or.

Cardiothoracic Surgeon Final

I find that read genuinely persuasive, and it changes my position from aspirin-alone to a bounded course. Ticagrelor added to aspirin for three months, then de-escalated to aspirin monotherapy on schedule — not left open-ended. Given his age and how recently he's had major surgery, I want an explicit stopping point rather than a decision to revisit indefinitely.

Regimen selected
Ticagrelor
P2Y12 Inhibitor (Reversible) · 90 mg twice daily, 3-month course
Added for a time-limited course per TOP-CABG, where 3 months was noninferior to 12 for patency and carried significantly less bleeding; TOP-CABG had no aspirin-alone arm, so the added benefit over aspirin itself rests on DACAB, which POPular CABG did not reproduce.
Aspirin
COX-1 Inhibitor · 81 mg daily, continued indefinitely
Standard post-CABG antiplatelet backbone, continued unchanged before, during, and after the ticagrelor course.
Warfarin / Direct Oral Anticoagulant
Anticoagulation — Ruled Out
No separate indication for anticoagulation — no atrial fibrillation, mechanical valve, or VTE history; graft patency is a platelet-mediated process, not one anticoagulation is indicated to address here.
Where this was left

Ticagrelor 90 mg twice daily added to aspirin 81 mg for an explicit 3-month course, with a scheduled de-escalation to aspirin monotherapy at that point rather than an open-ended continuation decision.

The underlying trial conflict — DACAB's positive patency signal against POPular CABG's null result — was not resolved by this case, only navigated using the newer de-escalation data:

Both physicians agreed the 3-month bounded course was the most defensible reading of a genuinely unsettled evidence base, given his age and recent surgery made an open-ended 12-month commitment the harder position to justify either way.

Educational content only — a composite teaching case, not a real patient encounter or a substitute for clinical guidance. About These Cases →