Coronary artery disease (CAD) is a common condition where plaque buildup narrows the arteries supplying blood to the heart muscle. This process, known as atherosclerosis, limits the flow of oxygen and nutrients, which can ultimately lead to a heart attack. Multivessel disease (MVD) is a widespread and severe manifestation of CAD, affecting multiple major blood vessels of the heart. Understanding this condition, how it is identified, and the treatment approaches available is important for managing heart health.
Defining Multivessel Coronary Artery Disease
Multivessel disease is defined as a significant narrowing or blockage, typically at least 70% stenosis, in two or more of the major coronary arteries. These arteries deliver oxygenated blood to the heart muscle, and their compromise places a large portion of the heart at risk. The main vessels include the Left Anterior Descending (LAD), the Left Circumflex, and the Right Coronary Artery (RCA).
The cause of MVD is the progressive accumulation of fatty deposits, cholesterol, and cellular waste products—known as plaque—on the inner walls of the arteries. This buildup thickens and stiffens the vessel walls, a condition called atherosclerosis. When multiple major arteries are affected, the overall burden of disease on the heart is significantly higher than in single-vessel disease.
The involvement of multiple blood vessels increases the complexity of treatment and carries a higher risk profile for adverse events. This is due to the potential for a larger area of heart muscle to be deprived of blood flow (ischemia), especially under physical or emotional stress. MVD signifies a widespread and advanced stage of coronary artery disease that requires aggressive medical management.
Symptoms and Diagnostic Procedures
The clinical presentation of MVD often involves symptoms signaling that the heart muscle is not receiving enough blood flow, particularly during periods of increased demand. The most common symptom is angina, which is chest pain or discomfort felt as pressure, squeezing, or a burning sensation. This pain frequently radiates to the arm, neck, or jaw and often occurs during physical exertion or stress.
Other signs include shortness of breath, particularly with activity, and generalized fatigue. In some patients, MVD can manifest as “silent ischemia,” meaning the heart suffers from a lack of oxygen without the patient experiencing any pain. Clinicians use a sequential approach to confirm the diagnosis and determine the extent of the disease.
An initial evaluation often includes an electrocardiogram (ECG) and a stress test. Stress testing, done through exercise on a treadmill or with pharmacological agents, helps reveal signs of ischemia that appear when the heart is working hard. While a standard ECG stress test may have limited accuracy, imaging stress tests, such as nuclear or echocardiographic studies, can more accurately identify areas of the heart muscle that are not receiving sufficient blood flow.
The gold standard for diagnosing MVD and counting the number of affected vessels is coronary angiography. This invasive procedure involves inserting a catheter, usually through the wrist or groin, and threading it up to the coronary arteries. A contrast dye is then injected, allowing the arteries to be visualized on an X-ray screen to identify the location and degree of narrowing in each major vessel.
Foundational Medical and Lifestyle Treatment
The management of multivessel disease is anchored in foundational medical therapy and lifestyle modifications, regardless of whether a patient requires invasive procedures. This dual approach aims to slow the progression of atherosclerosis, manage symptoms, and prevent complications like heart attack or stroke.
Pharmacological treatment focuses on several classes of medications that address different aspects of the disease. Antiplatelet agents, such as aspirin and P2Y12 inhibitors like clopidogrel, reduce the risk of clot formation within the narrowed arteries. Statins are prescribed to lower cholesterol levels, stabilizing existing plaques and preventing new ones from forming.
Beta-blockers slow the heart rate and reduce blood pressure, which decreases the heart muscle’s demand for oxygen, relieving angina symptoms and reducing strain. Angiotensin-converting enzyme (ACE) inhibitors or Angiotensin II receptor blockers (ARBs) are used to manage blood pressure, protecting the heart and blood vessels from further damage.
Lifestyle changes are equally important and involve a long-term commitment. Dietary modifications often involve adopting heart-healthy eating patterns like the Mediterranean diet or the Dietary Approaches to Stop Hypertension (DASH) diet. These diets emphasize fruits, vegetables, whole grains, and lean proteins while limiting saturated fats and sodium.
Exercise programs, often initiated through cardiac rehabilitation, are fundamental to improving cardiovascular fitness and quality of life. These programs involve a personalized, supervised regimen of endurance and resistance training, along with education on risk factor management. Smoking cessation is also non-negotiable, as tobacco use accelerates the progression of coronary artery disease.
Surgical and Procedural Revascularization Options
For many patients with MVD, restoring adequate blood flow to the heart muscle requires revascularization procedures. The two main invasive options are Percutaneous Coronary Intervention (PCI), which involves stenting, and Coronary Artery Bypass Grafting (CABG), which is open-heart surgery.
Percutaneous Coronary Intervention is a minimally invasive procedure performed in a cardiac catheterization lab. A catheter is inserted through a small puncture, usually in the wrist or groin, and guided to the blocked coronary artery using X-ray imaging. A thin wire is advanced across the blockage, and a balloon-tipped catheter is inflated to compress the plaque against the artery wall. A stent, often coated with medication to prevent re-narrowing, is then deployed to keep the artery permanently open. PCI is considered for less complex MVD, determined by the location and anatomy of the blockages.
Coronary Artery Bypass Grafting is a major surgical operation that provides a bypass around the narrowed segments of the coronary arteries. The surgeon harvests a healthy blood vessel, typically an artery from the chest wall or a vein from the leg, to use as a graft. The graft is then sewn onto the blocked coronary artery, connecting it to the aorta to reroute blood flow and bypass the obstruction. CABG is often the preferred choice for patients with more diffuse disease, blockages in the left main coronary artery, or those with diabetes.
The choice between PCI and CABG is a complex decision made by a multidisciplinary “Heart Team” of cardiologists and cardiac surgeons. This decision relies on several factors, including the patient’s health, age, and the severity and anatomical complexity of the blockages. A tool called the SYNTAX score is used to grade the complexity of the coronary anatomy. For patients with a high SYNTAX score, indicating complex disease, CABG is associated with better long-term outcomes than PCI.