There is a large number of drug controlled-delivery devices available to choose from. To select one, the process needs to start by considering what drug to use (an indication, the desired outcome), have a full understanding of its optimal dosing, pharmacokinetics and pharmacodynamics, its physical properties, and toxicokinetics, and determine what would be an optimal mode of delivery (oral, dermal, buccal, intramuscular, etc.). Once this is known, the actual development of the device would be (relatively) easy.

The biggest and first most concern would be drug resistance. In recent times, increasing evidence indicates that there is variability in response to anti-platelet therapy and patients who have a higher level of platelet reactivity are at an increased risk of recurrent cardiovascular thrombotic events. But anyways this post is really a salient aspect in drug delivery systems regarding this class of drugs.

Implantable anticoagualnt devices would only appear to be effectual if the patient agreed to such services.
Oral agents are very effective and offer a multiude of choices as to drug selection as well as value. The missing point as noted in the question is patient complaince. A mechnical device may address this, however the cost of the device; as well as the liability associated with over-de-coaugualtion would need to be seriously considered for liability purposes. MD titration vists for effectivness would also be neded to calcualte the overal savings. Refilling the device is another expense related to this type of therapy that would not be present for a compliant patient taking oral meds. Healthcare overall is looking for reduction in overll costs, you are right re-admissions are expense. More need to be known for such devices to remove the patient from the non-compliant bucket. Tom

There is a systems under patent WO2002076344 A1 who should be iteresting to take in consideration.
A method for improving cardiac function in a subject, the method comprising: implanting in said subject a sustained release dosage form, said sustained release dosage form comprising a drag delivery device and a cardiac drag, and administering said cardiac drag from said dosage form into said subject, for a period of at least 24 hours, in an dose sufficient to cause a measurable improvement in cardiac function.

I very much doubt that it would be worth implanting a device that delivers a "drag" (I assume you mean a drug) for 24 hours only.

I mentioned the description of the implanted device using the words of the authours in their patent application.
In any case, they used the word "drag" to mean solvent drag. As I mentioned before, the authors patented (PAT N. WO 2002076344 A1) a Delivery of drugs from sustained release devices implanted in myocardial tissue or in the pericardial space.

The methods are particularly useful when delivery of a drag to the cardiac tissue is desired for an extended period of time to increase its effectiveness or to reduce the risk and/or severity of adverse side effects, or to reduce the amount (and therefore cost) of drug delivered.
In various aspects, the drag may be delivered at a low dose rate, e.g., up to about 0.01 microgram/hr, 0.10 microgram/hr, 0.25 microgram/hr, 1 microgram/hr, or 5, 10, 25, 50, 75, 100, 150, or generally up to about 200 microgram/hr. Specific ranges of amount of drug delivered will vary depending upon, for example, the potency. In one exemplary embodiment, a drug formulation is delivered at a low volume rate e.g., a volume rate of from about 0.01 microliters/day to about 2 ml/day. Delivery of a formulation can be substantially continuous or pulsate, and can be for a pre-selected administration period ranging from several hours to years.
The sustained release drag delivery devices can be any device, e.g., osmotic pumps (used with or without a catheter), biodegradable implants, electrodiffusion systems, electroosmosis systems, vapor pressure pumps, electrolytic pumps, effervescent pumps, piezoelectric pumps, electrochemical pumps, erosion-based systems, depots, microspheres, or electromechanical systems.
Cardiac conditions which are amenable to treatment according to the invention include any pathological conditions, especially a condition of the heart that is amenable to treatment by increasing the number of functional coronary blood vessels, e.g., an ischemic heart disease; cardiac arrhythmia; a cardio-myopathy; coronary angioplasty restenosis; myocardial infarction; atherosclerosis of a coronary artery; thrombosis; a cardiac condition related to hypertension; cardiac tamponade; and pericardial effusion.

Generally, embodiments of the invention include a method for improving cardiac function in a subject, the method comprising: implanting in said subject a sustained release dosage form, said sustained release dosage form comprising a drug delivery device and a cardiac drug, and administering said cardiac drag from said dosage form into said subject, for a period of at least 24 hours, in an dose sufficient to cause a measurable improvement in cardiac function.
Also included are methods wherein the dosage form is placed in the pericardial sac, or implanted within the myocardial tissue, or sprayed directly onto the heart. The drug delivery device can oe a pump, or bioerodable implant, or depot. Generally, the cardiac drag is selected from the group consisting of: an angiogenic factor, growth factor, calcium channel blocker, antihypertensive agent, inotropic agent, antiatherogenic agent, anti-coagulant, beta-blocker, anti-arrhythmic agent, anti-inflammatory agent, sympathomimetic agent, phosphodiesterase inhibitor, diuretic, vasodilator, thrombolytic agent, cardiac glycoside, antibiotic, antiviral agent, antifungal agent, antineoplastic agent, and steroid.