Table 1.
Pathophysiological risk factors for CAD
| Risk Factor | Basis |
|---|---|
| Connective Tissue Abnormalities52,56 | Skin Biopsies of 68% of 25 and 55% of 65 CAD Patients Showed Evidence of Irregular Collagen Fibrils and Fragmentation of Elastic Fibers That Is Thought to Weaken the Arterial Wall. |
| Vascular Type IV Ehlers-Danlos Syndrome52,57,58 and Marfan Syndrome59 | These Inherited Connective Tissue Disorders Affect the Skin, Joints, and the Walls of Blood Vessels. The Incidence of CAD Has Been Reported to Be Higher in Patients With These Conditions. |
| Recent Infection60-62 | Case-Control Studies Point to Recent Infection as a Potential Trigger of CAD, Possibly Related to Arterial Wall Damage Caused by Proteolytic, Oxidative, or Autoimmune Defects. Furthermore, the Incidence of CAD Has Been Reported to Be Higher During Certain Seasons, Which May Be Related to the Higher Incidence of Upper Respiratory Tract Infections During the Winter. |
| Hyperhomocysteinemia63-66 | Especially Apparent in Patients With Total Plasma Levels That Exceed 12 μmol/L. Associated Arterial Wall Abnormalities May Increase the Artery's Susceptibility to Mechanical Stress. |
| Fibromuscular Dysplasia28,67 | Affects the ICA More Commonly Than the VA. Present in Up to 23% of ICA Dissection Patients, Making It the Most Frequently Reported Associated Abnormality. Characterized by Irregular Segments of Stricture and Dilation in the Vessel. |
| Cystic Medial Necrosis2 | Focal Degeneration of the Elastic Tissue and Muscle of the Tunica Media, With the Development of Mucoid Material. There Is a Breakdown of the Collagen, Elastin, and Smooth Muscle, and an Increase in the Artery's Ground Substance. |
| Type 1 Osteogenesis Imperfecta68 | Interferes With the Production of Type 1 Collagen. In Some Cases, Collagen Synthesis Is Decreased, Whereas in Others, Structurally Defective Collagen Is Produced. |
| Anatomical Abnormalities12,69-72 | May Result in Blood Flow Disturbance Leading to Insufficient Collateral Circulation. The Atlantal Segment of the VA Is Commonly Anomalous. Arterial Redundancies (eg, Coils, Kinks, and Loops) and Increased Diameter of the Common Carotid Artery Are More Common in Patients With ICA Dissection. |
| Hypertension14,73-75 | Several Studies Have Pointed to Hypertension as a CAD Risk Factor. A Well-Designed Case-Control Study Reported a Statistically Significant Association in the Subgroup of VA Dissection Patients, but Not in the Overall CAD Group. |
| History of Migraine76-78 | Robust Odds Ratios Have Been Generated in Several Case-Control Studies Pointing to This Association—7.41 (95% CI 3.11-17.64) in 1 Study. |
| Autosomal Dominant Polycystic Kidney Disease79,80 | Has Been Reported in Association With CAD by Several Authors, Although the Frequency of This Association and the Mechanism Involved Are Unknown. |
| Antithyroid Autoimmunity81,82 | A Recent Case-Control Study Reported the Presence of Antithyroid Autoimmunity in 31.0% of 29 CAD Patients, Compared With 6.9% of 29 Non-CAD Stroke Patients (P = .041). There Have Also Been Recent Case Reports of ICA Dissection in Patients With Graves Disease. Immunologic Mechanisms May Contribute to the Vascular Damage That Is Thought to Initiate CADs. |
| EE Genotype of the E469K ICAM-1 Polymorphism83 | The EE Genotype Gives Rise to a Proinflammatory Tendency in Patients That May Predispose Them to Developing CAD. |
| Methylenetetrahydrofolate Reductase C677T Genotype63,65,66,84 | Mutation of This Genotype Leads to Elevated Serum Levels of Homocysteine. The Issue Is Controversial Because Studies Have Not Been in Agreement. |
| α-1-Antitrypsin Deficiency85-87 | Researchers Have Theorized That This Deficiency May Lead to a Fragile Vessel Wall That Is Predisposed to Dissection, but There Is Little Evidence to Support This Relationship. Only a Few Small Studies Have Reported on This Association, and Their Results Are Conflicting. |
| Oral Contraceptive Use60,77,78 | Studies That Have Considered This Issue Are in Conflict. Only 1 Small Study Showed That Current Use of Oral Contraceptives Was Associated With CAD. The Consensus of Researchers Is That No Good Evidence Exists Supporting This Association. |
| Cardiovascular Risk Factors10,14,61,78,88 | May Actually Be Protective. Atherosclerotic Changes, Hypercholesterolemia, Advanced Age, and Diabetes Are Reported to Be Either Not Associated or Significantly Less Prevalent in CAD Patients. |
CI indicates confidence interval; ICAM-1, intracellular adhesion molecule 1.