Coronary artery disease in patients with peripheral vascular disease

Amino-terminal pro-B-type natriuretic peptide and high-sensitivity C-reactive protein but not cystatin C predict cardiovascular events in male patients with peripheral artery disease independently of ambulatory pulse pressure

BACKGROUND

Patients with peripheral arterial disease (PAD) are at high risk for cardiovascular (CV) events. We have previously shown that ambulatory pulse pressure (APP) predicts CV events in PAD patients. The biomarkers amino-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity C-reactive protein (hs-CRP), and cystatin C are related to a worse outcome in patients with CV disease, but their predictive values have not been studied in relation to APP.

METHODS

Blood samples and 24-hour measurements of ambulatory blood pressure were examined in 98 men referred for PAD evaluation during 1998-2001. Patients were followed for a median of 71 months. The outcome variable was CV events defined as either CV mortality or any hospitalization for myocardial infarction, stroke, or coronary revascularization. The predictive values of log(NT-proBNP), log(hs-CRP), and log(cystatin C) alone and together with APP were assessed by multivariable Cox regression. Area under the curve (AUC) and net reclassification improvement (NRI) were calculated compared with a model containing other significant risk factors.

RESULTS

During follow-up, 36 patients had at least 1 CV event. APP, log(NT-proBNP), and log(hs-CRP) all predicted CV events in univariable analysis, whereas log(cystatin C) did not. In multivariable analysis log(NT-proBNP) (hazard ratio (HR) = 1.62; 95% confidence interval (CI) = 1.05-2.51) and log(hs-CRP) (HR = 1.63; 95% CI = 1.19-2.24) predicted events independently of 24-hour PP. The combination of log(NT-proBNP), log(hs-CRP), and average day PP improved risk discrimination (AUC = 0.833 vs. 0.736; P < 0.05) and NRI (37%; P < 0.01) when added to other significant risk factors.

CONCLUSIONS

NT-proBNP and hs-CRP predict CV events independently of APP and the combination of hs-CRP, NT-proBNP, and day PP improves risk discrimination in PAD patients.

Frequency of coronary artery disease in patients undergoing peripheral artery disease surgery

The prevalence of coronary artery disease (CAD) in patients with peripheral arterial disease (PAD) varies widely in published reports. This is likely due at least in part to significant differences in how PAD and CAD were both defined and diagnosed. In this report, the investigators describe 78 patients with PAD who underwent preoperative coronary angiography before elective peripheral revascularization and provide a review of published case series. Among the patients included, the number with concomitant CAD varied from 55% in those with lower-extremity stenoses to as high as 80% in those with carotid artery disease. The number of coronary arteries narrowed by ≥ 50% was 1 in 28%, 2 in 24%, and 3 in 19%; 28% did not have any angiographic evidence of CAD. The review of published research resulted in the identification of 19 case series in which a total of 3,969 patients underwent preoperative coronary angiography before elective PAD surgery; in the 2,687 who were described according to the location of the PAD, 55% had ≥ 1 epicardial coronary artery with ≥ 70% diameter narrowing. The highest prevalence of concomitant CAD was in patients with severe carotid artery disease (64%). In conclusion, despite sharing similar risk factors, the prevalence of obstructive CAD in patients with PAD ranges widely and appears to differ across PAD locations. Thus, the decision to perform coronary angiography should be based on indications independent of the planned PAD surgery.

Ambulatory pulse pressure predicts cardiovascular events in patients with peripheral arterial disease

BACKGROUND

Patients with peripheral arterial disease (PAD) are at high risk of cardiovascular (CV) events and often have hypertension with a high pulse pressure (PP). We studied the prognostic value of ambulatory blood pressure (ABP) in PAD patients with special reference to PP.

METHODS

98 consecutive males with PAD had 24-h ABP measurements. The mean age was 68 years and CV comorbidity was prevalent. The outcome variable was CV events defined as CV mortality or any hospitalization for myocardial infarction, stroke or coronary revascularization. The predictive value of ABP variables was assessed by Cox regression. 90 age-matched men free of CV disease served as controls.

RESULTS

During follow-up (median 71 months), 36 patients and seven controls had at least one CV event. In PAD patients, 24-h PP (hazard ratios, HR, 1.48 (95% confidence interval, CI, 1.14-1.92), p <0.01) predicted CV events. Office PP did not predict events in PAD patients (HR 1.15 (0.97-1.38), ns). In multivariate analysis, 24-h PP (HR 1.48 (1.12-1.95), p <0.01) remained a predictor of CV events.

CONCLUSIONS

Ambulatory PP predicts CV events in patients with PAD. ABP measurement may be indicated for better risk stratification in PAD patients.

Medical Optimisation Can Reduce Morbidity and Mortality Associated with Elective Aortic Aneurysm Repair

OBJECTIVES

Patients with aortic aneurysms have significant comorbidities which influence outcome. Our practice includes comprehensive assessment to identify comorbidities, allowing subsequent medical optimisation prior to aneurysm repair. The aim of this study was to assess this process and to identify any factors predictive of outcome.

DESIGN

Prospective observational study.

MATERIALS

Medical case notes of 200 patients referred with aortic pathology.

METHODS

Data analysed included preoperative, perioperative and postoperative factors. Multiple logistic regression analysis was performed to identify predictors of outcome.

RESULTS

Following assessment 17 patients (8.5%) were found to be unfit for intervention and 165 patients (82.5%) proceeded to aneurysm repair. In this group assessment uncovered previously undiagnosed cardiac, respiratory and renal comorbidity in 19%, 57% and 29% of patients respectively. Multiple logistic regression analysis indicated that optimisation by a renal physician reduced post-operative renal impairment (OR 0.12, 95% CI 0.03-0.45, P=0.002) while optimisation by a cardiologist reduced respiratory complications (OR 0.7, 95% CI 0.05-0.99, P=0.049). An abnormal echocardiogram was associated with pneumonia (OR 6.9, 95% CI 1.6-29, P=0.01) and death (OR 7.9, 95% CI 1.15-54, P=0.036).

CONCLUSION

Pre-operative assessment identifies previously undiagnosed comorbidity in a significant proportion of patients. Subsequent medical optimisation may reduce post-operative morbidity and mortality.

Myocardial ischaemia in patients with peripheral arterial disease

AIM

To study the relation between myocardial ischemia assessed with different techniques in patients with peripheral arterial disease (PAD) in comparison with a matched control group.

METHODS

Ninety-nine male patients with PAD and 94 age- and sex-matched control subjects without PAD or ischaemic heart disease performed a exercise treadmill test, dipyridamole Tc-99m sestamibi myocardial perfusion SPECT (MPS) (43 controls) and 48-h ambulatory ECG (AECG)-monitoring (43 controls).

RESULTS

Thirteen of 99 patients had irreversible and 24 of 99 had reversible perfusion defects in MPS in comparison with 0 of 43 and six of 43 of control subjects respectively (P<0.01). Thirteen of 84 evaluable patients experienced a total of 36 episodes of ST-depression in AECG in comparison with two episodes in two of 42 control subjects (P = 0.07). Out of 13 patients with ST-depression episodes only three had reversible ischaemia in MPS.

CONCLUSION

Most PAD patients with episodes of ST-segment depression have no reversible ischaemia as assessed with dipyridamole-stress MPS. Episodes of ST-segment depression may reflect types of myocardial ischaemia that are different from those detected by MPS.

Increased urinary albumin excretion rates can be a marker of coexisting coronary artery disease in patients with peripheral arterial disease

Coexisting coronary artery disease (CAD) is an important cause of morbidity and mortality in patients with peripheral arterial disease (PAD). Clinical evaluation and noninvasive tests have some important limitations for the detection of CAD in patients with PAD. The purpose of this study was to investigate whether urinary albumin excretion (UAE) was a sign of atherosclerotic involvement of coronary arteries in patients with PAD. Our study consisted of 65 consecutive patients (56 men, 9 women, mean age; 59.7+/-7.9 years) with PAD who underwent coronary angiography. Urinary albumin excretion was measured in 24-hour urine samples by immunoprecipitation technique. PAD was defined as the presence of > or =50% stenotic lesions in at least 1 of the iliac, femoral, popliteal, tibialis anterior, tibialis posterior, or peroneal arteries. CAD was defined as > or =25% diameter stenosis in at least 1 coronary artery. Patients without any coronary lesions were accepted as having normal coronaries. Age, sex, distributions of coronary risk factors, and UAE rates were compared between patients with and without CAD. Mean UAE was 17.9+/-15.6 mg/day in the total population. Thirty-seven percent of patients had CAD, and 63% had no coronary lesion. UAE rates were 22.33+/-18.74 and 15.32+/-13.01 mg/day in patients with CAD and those with normal coronary arteries, respectively (p = 0.021). Microalbuminuria was detected in 25% in patients with CAD and 12% in those without coronary artery lesions (p = 0.184). The difference was not statistically significant. The distributions of other risk factors and sex were not different between the 2 groups. These data suggest that in patients with PAD, urinary albumin excretion rates may be used to determine those with a high probability of CAD. Further studies are required to decide whether this noninvasive testing is appropriate in detecting high-risk patients.

An appraisal of different cardiac risk reduction strategies in vascular surgery patients

OBJECTIVES

to summarize existing evidence regarding the benefits and the risks of all available interventional and medical means aimed at cardiac risk reduction in patients undergoing vascular surgery.

DESIGN

review of the literature.

MATERIALS AND METHODS

a critical review of all studies examining the impact of various prophylactic cardiac maneuvers on perioperative outcome following vascular surgery was performed. Overall mortality, cardiac mortality and myocardial infarction rate were used as the outcome measures.

RESULTS

coronary artery bypass grafting is associated with a 60% decrease in perioperative mortality in patients undergoing vascular surgery, but in most of the cases this decrease does not outweigh the combined risk of the cardiac and the subsequent noncardiac vascular procedure. Data supporting the cardioprotective effect of percutaneous transluminal angioplasty in the perioperative setting are insufficient. beta-blockade has been shown to decrease perioperative mortality and cardiac morbidity in both high-risk (strong evidence) and low-risk (weak evidence) patients.

CONCLUSIONS

coronary revascularization is rarely indicated to simply get the patient through vascular surgery and should be reserved for patients who would need it irrespective of the scheduled vascular procedure. Among all available pharmacological agents, including beta-blockers, alpha-agonists, calcium channel blockers and nitrates, only beta-blockers have been proven to reduce the cardiac risk of vascular surgery.

Angiographic concurrence of coronary artery disease and aortoiliac lesions

The importance of recognizing the association between aortoiliac disease and coronary artery disease includes the following: (1) Long-term morbidity is higher and survival ratio poorer in patients with coronary heart disease compared with isolated lower extremity revascularization surgery. (2) Coronary artery bypass grafting is a relatively high-risk procedure in patients with severe vascular disease. (3) There is the prospect that the patient will eventually face simultaneous coronary artery and vascular surgery, or coronary artery angioplasty previous to aortoiliac surgery. The aim of this investigation is to know the frequency of the association of coronary artery disease with aortoiliac lesions and to stratify the risk factors related to such an association. In total, 65 men and 19 women (30 to 76 years of age) with a history of coronary heart disease underwent abdominal aortography after selective coronary artery and left ventricle angiography. Aortoiliac lesions were identified at angiograms. Relevant coronary artery disease was diagnosed when at least 1 coronary artery was obstructed > 50%. The frequency of association between aortoiliac and coronary artery lesions was established, as well as the relationship of these lesions to the following clinical variables: age, weight, height, smoking habit, history of coronary heart disease, systemic arterial hypertension, diabetes mellitus, intermittent claudication, glycemia, uricemia, and triglyceridemia. There were 36 patients (42.9%) with aortoiliac lesions. In 34 patients (40.5%) coronary artery disease was associated with aortoiliac lesions. Abdominal aortic dilations were found in 10 instances, abdominal aortic stenosis in 13 patients, and stenosis of the iliac arteries or their branches on 28 occasions. The variables statistically related to the presence of aortoiliac lesions were smoking habit and a history of intermittent claudication. The number of affected coronary arteries was directly related to the frequency of aortoiliac lesions. In the entire sample, 11 patients (13%) had no coronary artery disease, and 15 (17.9%) had 1-vessel, 24 (28.6%) 2-vessel, and 34 (40.5%) 3-vessel disease. The extent of coronary disease was directly related to the frequency and extent of aortoiliac lesions. Frequencies of aortoiliac lesions were strongly related to a history of smoking habit and intermittent claudication and directly related to the extent of coronary artery disease.

Episodes of ST-segment depression is related to changes in ambulatory blood pressure and heart rate in intermittent claudication

OBJECTIVE

To study the prevalence and circadian distribution of ischaemic ST-segment depression detected with ambulatory electrocardiographic monitoring (AECG) in patients with intermittent claudication (IC) as well as to study ambulatory blood pressure (ABP) and the relation of ischaemic episodes to variations in ABP and heart rate.

DESIGN

A total of 40 patients with a history of IC and an ankle/brachial-index (ABI) <0.9 performed: (i) 24-h AECG recordings, (ii) simultaneous 24 h recordings of ABP every 15 min (Spacelabs 90207), (iii) an exercise treadmill test (ETT). An ischaemic episode was defined as a transient ischaemic ST-segment deviation > or =1 mm lasting >1 min. Eleven patients were excluded from ECG analysis because of uninterpretable ECG caused by treatment with digoxin or technical problems.

RESULTS

Out of 29 patients, eight experienced a total of 15 episodes of ST-depression on AECG. The mean duration was 21+/-31 min. The majority of episodes (11 of 15) occurred between 6 and 12 a.m. In eight patients with ST-segment depression three had a history of ischaemic heart disease (IHD), four were hypertensives and four had signs of myocardial ischaemia on ETT. There were no significant differences between patients with and without ST-segment depression in ABP, walking performance or ABI. During ST-depression episodes systolic and diastolic blood pressure and heart rate were higher than day mean values; 178+/-41 vs. 166+/-30 mmHg (P= 0.09); 96+/-9 vs. 90+/-4 mmHg (P = 0.01) and 103+/-9 vs. 87+/-5 beats min(-1) (P < 0.01).

CONCLUSION

Silent myocardial ischemia occurred in about a third of patients with IC. Episodes of ischaemia were associated with an increased ABP and heart rate. Whether treatment of high blood pressure may reduce silent ischaemia and if this favourably influences outcome is a matter of further research.

QT dispersion is increased in diabetic patients with foot ulcer

QT dispersion, a measure of inhomogenous ventricular repolarization, was measured in diabetic patients with foot ulcer. We recruited 75 patients with non insulin-dependent diabetes mellitus: patients with neuropathic ulcer (n=15, NU group), with ischemic ulcer (n=20, IU group), with previous myocardial infarction (n=20, MI group) and without any diabetic microangiopathies (n=20, DC group). We also studied normal control subjects (n=15, NC group). The interlead variability of rate corrected QT interval (QTc dispersion) was calculated. QTc interval in the MI group was significantly higher than that in the NC or DC but showed no difference in the NU and IU groups. QTc dispersion in the IU (54+/-15 msec) as well as MI (60+/-21 msec) group were significantly higher than the NC (36+/-18 msec) or DC group (39+/-14 msec). This may be due to complicated coronary artery disease in the IU group. Furthermore, QTc dispersion was also increased (49+/-14 msec) in the NU group in which cardiac autonomic nervous dysfunction was suggested. Patients with both types of diabetic ulcer demonstrated increased QT dispersion due to atherosclerosis or neurological disorder.

Coronary and major vascular disease: aggressive screening and priority-based therapy

It is well know that atherosclerosis can simultaneously affect different vascular subsystems, and patients with diffuse atherosclerosis can be a major management problem both for preoperative evaluation and for intraoperative management. The authors have conducted a prospective study to evaluate the prevalence of coronary artery disease in arteriopathic patients, and vice versa, to assess the effectiveness of aggressive screening together with a priority-based approach. Study 1 consisted of 1,000 consecutive non-emergent patients who were affected by abdominal aortic or carotid disease and were screened for the presence of coronary artery disease before surgery with a newly developed clinical risk assessment. They were stratified into three risk categories with different preoperative evaluation strategies. When coronary artery disease was concomitantly demonstrated in these patients, the choice of surgical method was based on priorities, and the use of combined surgical procedures as required. In study 2, 1,000 consecutive patients that required coronary angiography for suspected coronary artery disease were screened for the presence of carotid or abdominal aortic pathology, directly in the cardiac catheter laboratory during coronary angiography, by obtaining views of the aortic arch and abdominal aorta. Surgical approaches paralleled those of study 1. The results for study 1 showed that 720 patients (72%) were affected by abdominal aortic disease, 238 (24%) by carotid disease and 42 (4%) by both pathologies. Significant coronary artery disease was found in 152 patients (15%), of these 123 (81.5%) were affected by abdominal aortic disease and 29 (18.5%) by carotid artery disease. Abdominal aortic surgery was performed directly or after myocardial revascularization, with an overall mortality rate of 4/718 (0.6%), and a perioperative myocardial infarction rate of 10/718 (1.4%). For patients with carotid artery disease, the completed screening and possible therapy for coronary artery disease resulted in an in-hospital mortality rate of 2/238 (0.8%), and a perioperative myocardial infarction rate of 2/238 (0.8%). There were no significant differences in these rates between patients with or without coronary artery disease. Results for study 2 showed that of the 1000 consecutive patients enrolled for suspicion of coronary artery disease, 767 (77%) were affected by significant coronary artery disease. Among these, 38 (4.9%) had a surgically correctable aortic disease and 31 (4%) a surgically correctable carotid disease, which was monolateral and bilateral in 22 (74%) and nine (26%) patients, respectively, and four (0.5%) were diagnosed with both pathologies. These arteriopathic patients were treated for their coronary and vascular disease with no in-hospital mortality nor perioperative myocardial infarction. In patients with multiple vascular involvement, both coronary and vascular surgery can be performed with low risk when aggressive screening and priority-based therapy are adopted.

The frequency and significance of silent myocardial ischemia due to hyoscine butylbromide use in peripheral angiography

PURPOSE

Hyoscine-N-butylbromide (HB) is an anticholinergic drug used in digital subtraction angiography of the aortoiliac region because it decreases bowel gas movement artifact. HB also causes an increase in heart rate. We investigated whether this could cause silent myocardial ischemia (SMI) in susceptible patients during peripheral angiography.

METHODS

Thirty-six patients undergoing peripheral angiography were randomized into two groups, with 17 patients receiving 20 mg HB intraarterially during the angiogram and 19 patients receiving no drug. All patients were fitted with a Holter monitor that recorded the electrocardiogram before, during, and after the angiogram. Heart rate trends and ST segments were then analyzed.

RESULTS

Patients given HB had a statistically significant rise in heart rate compared with the control group. Although the difference was not statistically significant, two (12%) patients receiving HB had procedural ST depression compared with none in the control group. Pre- and postprocedural episodes of ST depression were common, occurring in 41% of patients receiving HB and 37% of patients receiving no drug, and were associated with an increase in heart rate.

CONCLUSION

The infrequent episodes of procedural SMI, potentially caused by the positive chronotropic effects of HB, are probably insignificant when compared with the high frequency of SMI episodes occurring outside the procedure.

Assessment of cardiac risk before aortic reconstruction: noninvasive work-up using clinical examination, exercise testing, and dobutamine stress echocardiography versus routine coronary arteriography

In this prospective study we evaluated the efficacy of a battery of noninvasive tests including clinical evaluation (CE), exercise testing (ET), and dobutamine stress echocardiography (DSE) for assessment of cardiac risk in 90 patients indicated for aortic reconstruction. As the gold-standard reference technique, coronary arteriography was performed in each patient after noninvasive evaluation. The sensitivity of CE was low (61%). ET proved to be more sensitive (71.4%) and highly specific (95.8%) but feasibility (77%) and diagnostic accuracy (42%) were low. DSE demonstrated acceptable sensitivity (78%) and specificity (75.5%) with high feasibility (94.5%) and diagnostic accuracy (100%). None of the four patients with false negative ET results and only one of seven with false-negative DSE required coronary bypass. On the basis of these findings we conclude that a combination of CE and ET with DES, if necessary, can reliably assess cardiac risk before aortic reconstruction. Noninvasive assessment is a reliable alternative to routine coronary arteriography.

[Chronic obliterative arterial disease of the lower limbs in the coronary patient: prevalence and prognostic incidence. The Monica Toulouse register]

PURPOSE

This study was aimed at evaluating the prevalence of peripheral arterial disease of the lower extremities and its prognostic value in a population of patients from the Haute-Garonne department, who were hospitalized for acute coronary artery disease.

METHODS

Between 1985 and 1991, four thousands three hundred and sixty-eight patients (3,680 males and 688 females) presenting with acute coronary artery disease were included in the study.

RESULTS

The prevalence of peripheral arterial disease of the lower extremities was 13.4%, increasing with age and being higher in male patients. In regard to patients hospitalized for acute myocardial infarction (n = 2,417), independent relationships were observed between the 28-day mortality and the following: patient's age (odds ratio: 1.02; 95% confidence interval: 1.01-1.04; P < 0.0005), female gender (odds ratio: 1.32; 95% confidence interval: 1.17-1.54; P < 0.002), inclusion in the study (odds ratio 0.95; 95% confidence interval: 0.90-0.99; P < 0.02), previous coronary artery disease (odds ratio: 2.88; 95% confidence interval: 2.32-3.48; P < 0.0001), and peripheral arterial disease (odds ratio: 1.61; 95% confidence interval: 1.26-2.06; P < 0.0001).

CONCLUSION

The prevalence of peripheral arterial disease of the lower extremities is high in patients with acute coronary artery disease in both genders, whatever the age. This disease is therefore an independent marker of mortality for acute myocardial infarction. Easy diagnosis of peripheral arterial disease of the lower limbs by measurement of the ankle pressure index allows identification of patients prone to death from acute myocardial infarction.

The role of screening blood tests in patients with arterial disease attending vascular outpatients

OBJECTIVE

To evaluate the benefits of a policy of performing screening blood tests in new patients with arterial disease referred to the vascular outpatients department.

METHODS

Clinical audit over a 12-month period of all new referrals with arterial disease to the vascular outpatients department at the Leicester General Hospital.

RESULTS

Two hundred and seventy-two patients had at least one blood test performed at their outpatient visit. All of these patients had a full blood count performed, of which 21 results (21%) were abnormal. Further investigation of patients with abnormal results revealed one case of bladder cancer, one case of leukaemia and one patient with polycythaemia. Urea and electrolytes were measured in 269 patients (99%). Of these, 26 (10%) were expectedly abnormal in patients with known renal impairment. A further 27 patients (10%) were identified to have some degree of unrecognised renal impairment. Serum non-fasting glucose was measured in 252 patients (93%). There were 11 unexpectedly raised results, but further investigation of these patients only diagnosed one of these patients as diabetic. Serum cholesterol was measured in 201 patients (74%). One hundred and thirty-two patients (66%) had an abnormally raised serum cholesterol level. Of these, only 12 patients (6%) were known to have hyperlipidaemia.

CONCLUSIONS

Screening new patients with arterial disease in vascular outpatients does identify significant abnormalities, in particular renal impairment and hyperlipidaemia. Correction of these abnormalities may reduce the morbidity associated with contrast induced nephrotoxic acute renal failure, and also contribute to secondary prevention of vascular events associated with raised lipids.

Cholesterol management in general practice

Ninety general practitioners from the Fylde coast of Lancashire responded to a questionnaire regarding lipid management, revealing that only 22% aim for a target total cholesterol of < or = 5.2 mmol/l in patients with established ischaemic heart disease. One third are reassessing the cholesterol in these patients at yearly intervals or less frequently, and 36% select 65 years or less as the upper age limit for screening. Approximately 50% of GPs screen for hypercholesterolaemia in patients with cerebral or peripheral vascular disease. Primary screening and treatment of hypercholesterolaemia within the 'at risk' asymptomatic population is well established with 72% of GPs screening hypertensives, 88% screening diabetics and almost all screening patients with an adverse family history, but the therapeutic cholesterol targets vary widely between individual practitioners.