Robert J. Lusby

Carotid plaque histology using real-time ultrasonography: Clinical and therapeutic implications☆☆☆

To evaluate the ability of ultrasonographic imaging to detect plaque hemorrhage in carotid atheroma, a study was undertaken that compared pathologic findings to preoperative ultrasonographic findings. Ultrasonography identified two plaque categories based on the heterogeneous and homogeneous echo patterns of the lesions studied. Heterogeneous lesions accounted for 91 percent of intraplaque hemorrhages (30 of 33) and 100 percent of ulcerated lesions (15 of 15). In 41 of 50 specimens (82 percent), ultrasonography correctly identified the presence or absence of plaque hemorrhage. False-negative studies (3 of 50) were due to the minute foci of remote hemorrhages. False-positive studies (6 of 50) resulted from plaques that contained large amounts of lipid or cholesterol. Preoperative ultrasound carotid imaging can be used to detect the histologic characteristics of plaque. Since recent clinicopathologic studies have implicated intraplaque hemorrhage and ulceration in symptomatic carotid disease, this information may be of value in choosing therapy, especially for the asymptomatic patient.

The natural history of asymptomatic carotid artery disease

PURPOSE The purpose of this article is to determine the natural history of carotid artery disease among asymptomatic patients with cervical bruits or other risk factors for stroke and to study the value of duplex ultrasonography in predicting future neurologic events. METHODS Two hundred forty-two asymptomatic, unoperated patients, referred for evaluation of asymptomatic carotid artery disease, were followed prospectively with duplex ultrasonography. RESULTS Fifteen ischemic strokes (6.2%) and 20 transient ischemic attacks (TIA) (8.3%) occurred in 34 patients during a mean follow-up of 27.4 months. Annual stroke, TIA, and combined event rates were 2.7%, 3.6%, and 6.2%, respectively. Although patients with 80% to 99% lesions had a 20.6% annual event rate, most events occurred contralateral to these lesions; the vessel-specific annual event rate for 80% to 99% disease was 5.1%. Only one of 15 strokes occurred ipsilateral to an 80% to 99% stenosis. Echolucent plaques were associated with TIA and stroke (5.7% annual vessel event rate vs 2.4% for echogenic plaques, p = 0.03). Disease progression was highly correlated with TIA and stroke (p < 0.0001), but it usually occurred in association with rather than before ischemic events, thus proving more useful in explaining pathogenesis than in predicting future events. There was no association between aspirin use and TIA, but patients taking aspirin had a threefold higher annual stroke rate (1.6% vs 4.8%, p = 0.027). CONCLUSIONS This study, while confirming significant risk for asymptomatic patients with critical stenosis or echolucent plaque, demonstrates the importance of contralateral disease and the absence of orderly progression from minimal disease through high-grade stenosis to symptomatic cerebral ischemia. TIA and stroke commonly occur in association with abrupt, unpredictable, quantum changes in carotid artery disease.

Complications of carotid endarterectomy.

Complications associated with carotid endarterectomy range from local nerve injuries and difficulties in controlling blood pressure to transient or permanent neurologic deficits and death. A thorough knowledge of such possible complications and of techniques to avoid and manage them is essential. This article reviews the anatomic and technical factors that relate to such complications and discusses their possible causes and management.

High-Intensity Progressive Resistance Training Improves Flat-Ground Walking in Older Adults with Symptomatic Peripheral Arterial Disease

To assess the efficacy of whole‐body progressive resistance training (PRT) as a treatment for the symptoms of peripheral arterial disease (PAD) in older adults.

Preliminary evidence that low ankle-brachial index is associated with reduced bilateral hip extensor strength and functional mobility in peripheral arterial disease

OBJECTIVE Peripheral arterial disease (PAD) has been associated with skeletal muscle pathology, including atrophy of the affected muscles. In addition, oxidative metabolism is impaired, muscle function is reduced, and gait and mobility are restricted. We hypothesized that greater severity of symptomatic PAD would be associated with lower levels of muscle mass, strength, and endurance, and that these musculoskeletal abnormalities in turn would impair functional performance and walking ability in patients with PAD. METHODS We assessed 22 persons with intermittent claudication from PAD in this cross-sectional pilot study. Outcome assessments included initial claudication distance and absolute claudication distance via treadmill protocols and outcomes from the 6-minute walk (6MW). Secondary outcomes included one repetition maximum strength/endurance testing of hip extensors, hip abductors, quadriceps, hamstrings, plantar flexors, pectoral, and upper back muscle groups, as well as performance-based tests of function. Univariate and stepwise multiple regression models were constructed to evaluate relationships and are presented. RESULTS Twenty-two participants (63.6% male; mean [standard deviation] age, 73.6 [8.2] years; range, 55-85 years) were studied. Mean (standard deviation) resting ankle-brachial index (ABI) was 0.54 ([0.13]; range, 0.28-0.82), and participants ranged from having mild claudication to rest pain. Lower resting ABI was significantly associated with reduced bilateral hip extensor strength (r = 0.54; P = .007) and reduced whole body strength (r = 0.32; P = .05). In addition, lower ABI was associated with a shorter distance to first stop during the 6MW (r = 0.38; P = .05) and poorer single leg balance (r = 0.44; P = .03). Reduced bilateral hip extensor strength was also significantly associated with functional outcomes, including reduced 6MW distance to first stop (r = 0.74; P = .001), reduced 6MW distance (r = 0.75; P < .001), and reduced total short physical performance battery score (worse function; r = 0.75; P = .003). CONCLUSIONS Our results suggest the existence of a causal pathway from a reduction in ABI to muscle atrophy and weakness, to whole body disability represented by claudication outcomes and performance-based tests of functional mobility in an older cohort with symptomatic PAD. Longitudinal outcomes from this study and future trials are required to investigate the effects of an anabolic intervention targeting the muscles involved in mobility and activities of daily living and whether an increase in muscle strength will improve symptoms of claudication and lead to improvements in other functional outcomes in patients with PAD.

Case Scenarios to Assess Australian General Practitioners’ Understanding of Stroke Diagnosis, Management, and Prevention

Background and Purpose— Stroke represents the third-leading cause of death in Western society. Prompt and appropriate intervention for those with stroke or at risk of stroke is highly dependent on general practitioners’ (GPs’) knowledge and referral practices. Methods— We randomly selected 490 eligible GPs from New South Wales, Australia, to complete our self-administered questionnaire. Case scenarios were used to assess GPs’ knowledge of transient ischemic attack/ stroke risk factors, stroke prevention strategies, and management of asymptomatic and symptomatic patients. Results— We received 296 completed questionnaires (60% response rate). Nearly all GPs (286, 96.6%) strongly agreed or agreed that stroke is a medical emergency. Most were aware that management by multidisciplinary teams improves outcomes (strongly agree or agree, 279; 94.3%). GPs endorsed the effectiveness of aspirin and warfarin in reducing stroke morbidity. GPs also were aware of the benefit of carotid endarterectomy (CEA) for symptomatic patients with >80% carotid stenosis but were less aware of the value of CEA for symptomatic patients with moderate stenosis. Vascular surgeon was the specialist of choice for referral of patients with high-grade carotid stenosis. Few GPs reported having seen the Cochrane Collaboration reviews of CEA for symptomatic (3.0%) and asymptomatic (1.7%) patients. Conclusions— GPs were well apprised of the evidence to support CEA for symptomatic patients with high-grade carotid stenosis. Our findings, however, invite more purposeful and effective education of GPs about stroke prevention, diagnosis, and management if optimal outcomes are to be realized.

Vascular disease risk factor management 4 years after carotid endarterectomy: are opportunities missed?

Background:  Because a large percentage of patients surviving carotid endarterectomy (CEA) subsequently die from a vascular cause, the aim of the present paper was to determine risk factor management for a cohort of patients 4 years after their CEA.

Statin therapy and carotid endarterectomy: a review of trends in New South Wales, 1990–2004

Background:  The number of patients requiring carotid endarterectomy in our hospitals had been noted to be declining. Hence, our aim was to look at the numbers of carotid interventions in our State to see whether this trend was more pervasive and to look at trends in statin prescriptions over the same time‐course.

Deep femoral reconstruction

Deep femoral reconstruction effectively opens a stenotic or occluded deep femoral artery with restoration of flow to the main collateral blood supply to the leg. Revascularization of the deep femoral artery can be critical to limb salvage when the superficial femoral artery is occluded. The deep femoral artery, being a supply artery to the thigh, is relatively spared of extensive atheromatous disease. In up to 75% of patients stenosis is limited to the proximal 1–2 cm, often being the result of a continuation of a common femoral artery plaque. In the remaining patients the disease may extend to the next major branch, commonly the lateral circumflex, or first perforating branches. Occasionally, the plaque extends to the second or third perforating branches, so correction requires more extensive exposure and repair.