Microvasculature and incident atrioventricular conduction abnormalities in the Multi-Ethnic Study of Atherosclerosis (MESA).

Abnormalities of the microvasculature are linked to major cardiac events, but their role in the development of atrioventricular conduction abnormalities (AVCA) is unknown. We examined the association between central retinal arteriolar equivalent (CRAE), a measure of the microvasculature, and incident AVCA. This analysis included 3975 participants free of AVCA at baseline from the Multi-Ethnic Study of Atherosclerosis (MESA). Incident AVCA was defined as a composite of new heart rate-adjusted PR interval ⩾ 200 ms (first-degree AV block) and advanced block (second-degree or complete AV block) detected from the MESA exam 5 electrocardiogram (ECG). CRAE was measured from retinal photographs at exam 2. Both ECGs and retinal photographs were collected using standardized methods and read and graded at central core labs. Incident AVCA were present in 7.4% (n=290) of the participants, of which 94% were first-degree AV block. Incident AVCA were increasingly more common in participants with narrower CRAE (4.6% in Q4, 6.4% in Q3, 7.0% in Q2 and 10.8% in Q1, p-value for trend < 0.0001). The socio-demographic and cardiovascular disease risk-adjusted odds of incident AVCA in the Q1 group (the group with the narrowest retinal arteriolar diameter) was nearly twice the odds in the Q4 group (OR: 1.68, 95% CI: 1.15-2.51). This association remained significant after adjustment for major ECG abnormalities and incident cardiovascular disease (Q1 vs Q4, OR: 1.65, 95% CI: 1.01-2.71). In conclusion, narrower retinal arteriolar caliber is associated with development of new AV conduction abnormalities.

Mortality in patients with premature lower extremity atherosclerosis.

OBJECTIVE: Lower extremity peripheral artery disease occurs mostly in the elderly and is associated with high mortality. Limited data are available regarding long-term mortality in patients with premature lower extremity atherosclerosis (PLEA). Our objective was to determine the all-cause mortality and its predictors in younger PLEA patients. METHODS: We studied patients with severe PLEA who were <55 years of age at diagnosis and treated at a single academic vascular center between 1998 and 2010. Data were collected prospectively at the initial evaluation for vascular care. National Death Index and hospital records were used to determine all-cause mortality. Demographic and clinical characteristics were summarized using count (%), mean (standard deviation), or median (interquartile range), and associations with aspirin use were tested using χ2 test, t-test, or Wilcoxon test. Survival times were estimated using Kaplan-Meier estimates, and associations with covariates were tested using simple and multivariable Cox proportional hazards models. RESULTS: A total of 564 patients were analyzed (46% female; 20% nonwhite; mean age 49.4 [6.4] years). Ninety-five percent of patients had ≥2 cardiovascular risk factors, 31% had coronary artery disease (CAD), and 10% had a history of cancer. During median follow-up of 5.6 years (interquartile range, 2.3-8.3 years), 108 deaths (19%) were recorded. Two-year estimated mortality (standard error) was 6% (0.01), and 5-year estimated mortality was 16% (0.02). In univariate regression analysis, patient age (P=.04), prior amputation (P<.01), history of cancer (P=.03), and established CAD (P=.04) were associated with increased risk of mortality. Aspirin use and lipid-lowering therapy at the time of first evaluation were associated with improved survival (P<.01 and P=.02, respectively). A multivariable Cox proportional hazards model identified age (hazard ratio [HR] for 5-year increase, 1.17; 95% CI, 1.01-1.36; P=.04), prior amputation (HR, 1.99; 95% CI, 1.18-3.34; P=.01), history of cancer (HR, 2.35; 95% CI, 1.36-4.07; P<.01), and CAD (HR, 1.76; 95% CI, 1.16-2.67; P<.01) as independent predictors of mortality in patients with PLEA. Importantly, history of aspirin use had a significant protective effect (HR, 0.45; 95% CI, 0.30-0.69; P<.01). The impact of lipid-lowering therapy was no longer significant in multivariable modeling. CONCLUSIONS: Patients with PLEA demonstrate high all-cause mortality. No traditional cardiovascular risk factors predicted mortality. Aspirin therapy at the time of first evaluation was a significant and independent predictor of improved survival in patients with PLEA.