Abstract: Although the target compound "DAPT" is often associated with oncology as a gamma-secretase inhibitor, the provided literature exclusively discusses DAPT in the context of Dual Antiplatelet Therapy for cardiovascular and neurovascular interventions. This review synthesizes the provided clinical and pharmacological data on Dual Antiplatelet Therapy (DAPT). DAPT, typically a combination of aspirin and a P2Y12 receptor inhibitor, is a cornerstone treatment for preventing thrombotic complications following percutaneous coronary intervention (PCI), stent implantation, and for secondary stroke prevention. The primary clinical challenge of DAPT is balancing the prevention of ischemic events (such as myocardial infarction and stent thrombosis) against the elevated risk of major bleeding. Recent clinical paradigms emphasize personalized therapy durations, including early aspirin withdrawal followed by P2Y12 inhibitor monotherapy, to optimize net clinical benefit.
1. Introduction
Dual Antiplatelet Therapy (DAPT) is a critical pharmacological strategy that combines aspirin with a P2Y12 receptor inhibitor [4]. While the specified research direction is oncology, the provided literature strictly evaluates DAPT within cardiovascular and neurovascular contexts; there is no mention of DAPT as an oncological agent in the source texts. In clinical practice, DAPT is primarily indicated for patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stents (DES) or drug-coated balloons (DCB), as well as for secondary stroke prevention [1][4][9]. The fundamental objective of DAPT is to prevent severe thrombotic complications, such as myocardial infarction (MI) and stent thrombosis, while minimizing the inherent risk of major bleeding [2][6]. Guidelines historically recommended 12 months of DAPT following acute coronary syndrome (ACS), but contemporary evidence has prompted a reevaluation of optimal treatment durations [1][2].
2. Pharmacological Activity
The pharmacological activity of DAPT centers on maximizing protection against short- and long-term postoperative stent or vessel thrombosis by comprehensively blocking platelet activation [4]. The clinical efficacy of DAPT is highly dependent on the duration of therapy and the specific clinical scenario. Extended-term DAPT (greater than 12 months) has been shown to significantly reduce the risk of MI and stent thrombosis, but this ischemic protection comes at the expense of increased major bleeding events [1]. Conversely, short-term DAPT (1 to 3 months) followed by P2Y12 inhibitor monotherapy maintains ischemic protection while significantly reducing bleeding risks in high-risk PCI populations [2][6]. In other structural heart interventions, such as transcatheter aortic valve replacement (TAVR), DAPT for 3 to 6 months is associated with a higher risk of major or life-threatening bleeding compared to single antiplatelet therapy (SAPT), without offering significant advantages in reducing stroke or all-cause mortality [8]. For secondary stroke prevention, DAPT reduces recurrent ischemic events but increases bleeding risk compared to aspirin alone [9].
3. Molecular Mechanism of Action
The molecular mechanism of DAPT involves the simultaneous blockade of multiple platelet activation pathways. Platelet adhesion at sites of vascular injury is initially mediated by the interaction of glycoprotein (GP) receptors (such as the GP Ib/V/IX complex and GPVI) with extracellular matrix proteins like von Willebrand factor and collagen [4]. Following adhesion, local factors such as adenosine diphosphate (ADP), thromboxane A2 (TXA2), serotonin, and thrombin amplify platelet activation via specific G protein-coupled receptors [4].
DAPT disrupts this amplification cascade through two distinct and complementary mechanisms:
1. Aspirin (Acetylsalicylic acid): Aspirin acts as an irreversible inhibitor of the cyclooxygenase 1 (COX1) enzyme. By blocking COX1, aspirin diminishes the production of TXA2, thereby preventing TXA2-promoted platelet activation and aggregation during pathological thrombus formation [4].
2. P2Y12 Inhibitors (e.g., clopidogrel, prasugrel, ticagrelor): These agents act as ADP receptor antagonists. They inhibit the activation of the P2Y12 receptor, which is a crucial pathway for the amplification of platelet activation and the formation of occlusive platelet-rich thrombi [4].
4. Structure-Activity Relationship (SAR)
The provided literature focuses exclusively on the clinical efficacy, safety, and meta-analyses of DAPT regimens rather than the chemical structure-activity relationships (SAR) of the individual antiplatelet agents. The texts distinguish between different classes of P2Y12 inhibitors—such as the thienopyridines (clopidogrel and prasugrel) and the cyclopentyltriazolopyrimidine (ticagrelor)—noting that more potent P2Y12 inhibitors like ticagrelor and prasugrel yield lower ischemic and mortality outcomes over clopidogrel in high-risk patients [2]. However, specific molecular modifications and their direct impact on target binding affinity are not detailed in the provided documents.
5. Current Limitations
The primary limitation of DAPT is the inherent and unavoidable trade-off between ischemic protection and bleeding risk. Prolonged DAPT exposes patients to a significantly higher risk of major bleeding complications [1][6]. In perioperative settings, managing patients on DAPT is particularly challenging; withholding DAPT for more than 2 days prior to coronary artery bypass graft (CABG) surgery reduces blood loss and transfusions, but the optimal management strategy for non-cardiac surgeries remains uncertain due to a lack of high-quality randomized evidence [5]. Furthermore, clinical trials exhibit significant heterogeneity in patient baseline risks, definitions of bleeding (e.g., BARC criteria), and timing of randomization, which complicates the establishment of a universal standard of care [1][6].
6. Future Perspectives
Future strategies for DAPT are moving toward highly personalized approaches that tailor the duration and intensity of therapy to individual patient profiles, balancing absolute ischemic and bleeding risks [1]. A major paradigm shift currently under investigation is the "early aspirin withdrawal" strategy, where DAPT is de-escalated to potent P2Y12 inhibitor monotherapy after 1 to 3 months. This approach has shown a high probability of reducing bleeding without compromising ischemic safety in high-risk PCI populations [2][6]. Additionally, as novel devices like drug-coated balloons (DCBs) become more prevalent, defining the optimal, potentially shorter, DAPT duration for these specific interventions will be a critical area of future randomized controlled trials [4].
