Complications Of Coronary Atherosclerosis Research Articles

Coronary artery remodelling in atherosclerosis: unfortunately unpredictable

Coronary heart disease is the main cause of mortality and morbidity worldwide, and occurs because of the growth and complications of coronary atherosclerosis. Therefore, efforts in the understanding of how atherosclerotic plaques grow and undergo complications, and in identifying predictors of such dramatic events are welcome and worthwhile. Atherosclerosis has long been considered a relentless process by which the accumulation of lipids and extracellular matrix leads to progressive lumen encroachment. Two notions in the past 20 years have dramatically altered this conception. One is that most cases of myocardial infarction likely derive from acute plaque complications (plaque fissuring in most instances), and not from progressive lumen stenosis1. The other is that the growth of atherosclerotic plaques is not necessarily towards the lumen, but may also occur towards the outer vessel layers, leading to an actual overall enlargement of the vessel, contrary to the previous tenet that atherosclerosis is similar to the encrustation of metal pipes in a building. This second aspect, although less appreciated in current literature than the burgeoning plethora of investigations on mechanisms of plaque rupture, is also fertile of important clinical consequences. In a series of human histopathological observations, Glagov et al .2 were the first to identify a significant direct correlation between the plaque area—calculated as the area defined externally by the internal elastic lamina (internal elastic membrane, IEM) and internally by the vessel lumen (intimal area) and the potential lumen area—i.e. the area circumscribed by the internal elastic lamina, taken as a measure of the area of the arterial lumen if no plaque had been present and the intima remained a virtual space. This finding indicated that, in general, the larger the plaque, the larger the vessel, and allowed the inference that plaques also grow towards the outside (‘positive remodelling’). These results have … *Corresponding author. Tel: +39 (0) 871 41512; fax: +39 (0) 871 402817. E-mail address : rdecater{at}unich.it

Ten-year follow-up of critically ill patients undergoing heart transplantation

Background: The long-term result following heart transplantation appears very good despite complications of coronary atherosclerosis and cancer. Critically ill patients supported with mechanical devices remain a growing and difficult group in which long-term results need to be defined. The objective of this study was to review the 10-year follow-up of critically ill patients who underwent heart transplantation after support with mechanical devices. Methods We retrospectively analyzed all patients who underwent heart transplantation from 1986 to 1999 at the Montreal Heart Institute. Results Twenty-two patients (22/199, 11%) underwent heart transplantation after support with intra-aortic balloon pumps ( n = 17) and total artificial hearts ( n = 5). One hundred seventy-seven patients (177/199, 89%) underwent heart transplantation without pre-operative mechanical assistance. Patients with pre-operative mechanical assistance were younger (41 ± 12 vs 48 ± 10 years old, p = 0.002), underwent a shorter waiting time to transplantation (2 ± 2 vs 19 ± 27 weeks, p = 0.004), and donor hearts had longer ischemic time (166 ± 63 vs 137 ± 49 minutes, p = 0.002) compared with patients without pre-operative mechanical assistance. One-month, 1-, 5-, and 10-year survival averaged 86% ± 7%, 67% ± 10%, 67% ± 10%, and 59% ± 12%, respectively, in patients with pre-operative mechanical assistance compared with 95% ± 2%, 88% ± 2%, 81% ± 3%, and 74% ± 4%, respectively, in patients without assistance, a significant difference ( p = 0.04) that is mainly related to higher operative mortality in the former group. Although, we found no difference between the 2 groups in the 10-year freedom rate from acute rejection, infection, cancer, and coronary atherosclerosis, sepsis was the cause of 4 early deaths among patients with pre-operative mechanical assistance. Conclusion Early and long-term survival was significantly decreased in critically ill patients with pre-operative mechanical assistance compared with other patients without pre-operative assistance. Sepsis is a dominant threat among patients who underwent heart transplantation with pre-operative mechanical assistance, and the lower survival is due mainly to the increased early mortality.

Degenerative, non-atherosclerotic cardiovascular disease in the elderly: A clinico-pathological survey

Cardiovascular disease, the major cause of death in the elderly, is mostly ascribable to complications of coronary atherosclerosis: angina pectoris, myocardial infarction, and sudden death. However, other degenerative diseases involving several cardiac structures exist, and should be distinguished from age-related cardiac changes. Extensive dystrophic calcification determines aortic stenosis, and may affect either a normally tricuspid or a congenitally bicuspid valve. Surgical valve replacement is now a low risk option, even in elderly persons, whereas the efficacy of balloon valvuloplasty is questionable. Aortic incompetence in adults and aged persons is mostly the consequence of aortic tunica media atrophy with anular ectasia, in the setting of nearly normal aortic leaflets. Mitral valve prolapse is the main cause of mitral incompetence; spontaneous cordal rupture is a late complication in the natural history of this disease, thus warranting prompt surgical valve repair or replacement. The entire spectrum of cardiomyopathies is observed in the elderly: dilated, hypertrophic, restrictive, arrhythmogenic. Cardiac amyloidosis is by far the most frequent secondary form and leads to congestive heart failure by impairing ventricular compliance. Idiopathic fibrosis of the specialized AV junction or dystrophic calcification of central fibrous body are the usual substrates of AV block, which requires pace-maker implantation. Nonrheumatic atrial fibrillation, due to fibro-fatty degeneration of the atrial musculature or dilated left atrium, carries a high risk of thromboembolic complications and cerebral accidents; oral anticoagulants have proven to be effective in preventing stroke. Aortic dissecting aneurysm is a spontaneous laceration, and usually a complication of longstanding systemic hypertension; exceptionally, spontaneous dissection may primarily occur in the coronary arteries. In conclusion, longevity at present is mostly threatened by cardiovascular disease, among which the role of degenerative, non-atherosclerotic disorders may be greater than thought.

Platelet-Suppressant Therapy in Patients With Coronary Artery Disease

Platelets may contribute to the pathogenesis of atherosclerosis and to the complications of coronary atherosclerosis, acute myocardial infarction, unstable angina, and sudden cardiac death. In addition, platelets may contribute to saphenous vein aortocoronary graft occlusion. Of 104 men with coronary artery disease, platelet survival (SURV) (chromium51 labeling) was shortened in 68% (3.1+/-0.03 days [average+/-SEM]; normal, 3.7+/-0.03 days; P greater than .001). Three platelet-suppressant drugs, sulfinpyrazone, clofibrate, and dipyridamole increased SURV. Saphenous vein graft occlusion was associated with shortened SURV. Of 36 men with occlusion of at least one graft, SURV was shortened in 35 (2.5+/-0.08 days), whereas in 19 with all grafts open, SURV was shortened in six (3.5+/-0.10 days; P less than .01). These drugs increased SURV (2.3 +/- 0.08 to 2.7 +/- 0.11 days; P less than 0.1) and were associated with improved graft patency (four of 32 grafts after initial bypass vs 30 of 34 grafts open after second operation).