A coronary stent is a small, mesh-like tube used in percutaneous coronary intervention (PCI) to treat narrowed or blocked coronary arteries. Its primary function is to act as a scaffold, mechanically propping the artery open to restore healthy blood flow to the heart muscle, typically after a blockage caused by atherosclerosis. Most modern stents are drug-eluting, coated with medication that helps prevent the vessel from re-narrowing over time. Yes, a person can have seven or more stents, although this is not a common scenario. This high number of implanted devices indicates severe and widespread coronary artery disease requiring multiple interventions over time.
Factors Determining the Need for Multiple Stents
The necessity for a high number of stents is rooted in the complexity and extensive nature of the patient’s underlying heart disease. One primary reason is diffuse disease, which describes widespread and long-segment narrowing throughout the coronary artery network. Treating these extensive lesions often requires placing multiple individual stents in a contiguous, overlapping fashion to cover the entire diseased length of the vessel.
The intricate anatomy of the coronary tree also contributes to the accumulation of stents, as blockages can occur simultaneously in multiple major branches. A patient may need stents in the main left anterior descending artery, the right coronary artery, and the circumflex artery, all within a single procedure or over several years. Each separate intervention adds to the total stent count.
Chronic Total Occlusions (CTOs)
In some instances, a patient may develop a Chronic Total Occlusion (CTO), a complete blockage that has been present for at least three months. CTOs are technically complex to treat and often require a series of devices, sometimes including multiple stents. This is necessary to successfully recanalize and maintain the patency of the long-occluded segment.
The decision to place multiple stents depends on the location and extent of the blockages, the overall condition of the patient’s vessels, and their clinical presentation. When lesions are particularly long—sometimes exceeding 20 millimeters—or involve a complex bifurcation, the interventional cardiologist may opt for several stents. This ensures complete coverage and optimal mechanical support for the artery wall.
Clinical Risks Associated with High Stent Burden
While multiple stents can be life-saving, the presence of a large amount of foreign material introduces clinical risks. One significant concern is In-Stent Restenosis (ISR), which occurs when scar tissue grows back inside the implanted stent, causing the artery to narrow again. Studies indicate that the risk of restenosis increases with the total number of stents, often being significantly higher for patients with three or more stents.
A second complication is Stent Thrombosis, the sudden formation of a blood clot within the stent that can lead to an acute heart attack. Multiple stents, especially in overlapping segments, can alter blood flow dynamics and increase the surface area where a clot might form. To mitigate this risk, patients must adhere to Dual Antiplatelet Therapy (DAPT), typically a combination of aspirin and a second antiplatelet medication.
The necessity of long-term DAPT itself carries inherent risks, as these medications reduce the blood’s ability to clot, increasing the risk of significant bleeding events. The duration of this therapy is carefully balanced by the physician against the patient’s overall bleeding risk. The high burden of hardware necessitates continuous, careful management of associated clotting and bleeding risks.
Alternatives When Stent Placement is No Longer Feasible
When a patient’s coronary anatomy becomes too diffused, complex, or heavily saturated with existing stents, placing additional devices may become less effective or too hazardous. The treatment strategy often shifts toward a more durable solution, primarily Coronary Artery Bypass Grafting (CABG) surgery. CABG involves using healthy blood vessels, or grafts, taken from another part of the body to create new pathways that bypass the blocked or diseased segments of the coronary arteries.
This surgical approach is particularly advantageous when blockages affect multiple vessels, when the left main coronary artery is severely narrowed, or when the disease is too diffuse for stents to reliably cover. For patients with severe, multi-vessel disease, CABG is often considered the superior long-term revascularization strategy, despite being a more invasive procedure with a longer recovery time.
Other alternatives may be considered, such as enhanced medical therapy focusing on lifestyle changes and aggressive medication to manage symptoms. Non-invasive procedures like Enhanced External Counterpulsation (EECP) or the use of drug-coated balloons can also be employed. These methods manage symptoms or treat in-stent restenosis without leaving permanent hardware behind.