Observational and Transversal Study of Stable Coronary Artery Disease Among Cardiology Patients

Introduction

Patients with peripheral artery disease (PAD) or significant coronary arterial disease (CAD) are all considered at high-risk for cardiac and cerebrovascular events. The common underlying atherosclerotic process and the concomitance of advanced stages in diverse arterial beds, justify why patients with PAD, including those who do not have cardiac symptoms, are in the same risk category of patients with known coronary artery disease.

The high significance of this topic influenced many different medical societies to develop guidelines for appropriate risk factors control, such as the Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II); the ACC/AHA 2005 Practice Guidelines for the management of patients with peripheral arterial disease and the IV Brazilian Guideline for Dyslipidemia and Atherosclerosis prevention from the Department of Atherosclerosis of the Brazilian Society of Cardiology. However, those recommendations are frequently not translated into clinical practice, as already demonstrated in this context and also in other clinical situations (tromborisk).

Several studies display multifactorial reasons for this gap, fluctuating from bad medical practice to poor patient’s treatment adherence. Moreover, it seems that patient’s awareness of their condition may influence the effectiveness of secondary prevention.

There is a lack of information about the Brazilian reality regarding the cardiovascular prevention guidelines implementation for specific populations. Hence, the primary objective of this study is to analyze the quality of secondary prevention in patients at the Vascular Surgery Clinic and at the Heart Institute of the Clinics Hospital from the University of São Paulo Medical School. We also evaluated, as a secondary objective, possible differences in prevention practice between patients with coronary disease and vascular surgical patients.

METHODS:
This is an observational and transversal study that was conducted at the University of São Paulo Medical School in the department of Vascular Surgery and in the Heart Institute of the Clinics Hospital, having been previously approved by the local Ethics Committee.

The main selection criteria was the presence of stable coronary artery disease for the cardiology patients, whereas at the Vascular Surgery, it was stable aortic disease (aneurysm/ dissection), carotid obstruction or peripheral obstructive arterial disease.

Patients were randomly selected at the ambulatory facility and at the hospital wards and were invited by medical students to participate of the study. After a written informed consent was obtained, patients were interviewed and had their medical records analyzed by the students.
The questionnaire was designed to identify the self-reported rate of the traditional atherosclerosis risk factors (hypertension, dyslipidemia, diabetes, smoking, sedentarism), if patients had received medical orientation regarding lifestyle modification (dietary advice, exercise prescription and smoking advisory) and the awareness of the patient about their condition. For this purpose, patients were asked to inform their medical diagnosis (“Do you know the main reason why you are treated for in this clinic?”) and if they knew the importance of cardiovascular prevention (eg:, for vascular patients “Do you know that if you practice exercise, quit smoking, control your blood pressure and cholesterol levels, besides the benefits for your vascular problem you can also prevent stroke and myocardial infarction?).
Medical charts were reviewed to compare the physicians and the patients reported diagnosis. We also obtained from the charts, the last available data in the past 2 years for blood pressure level, lipid profile and for diabetic patients, fasting glucose and glycated hemoglobin. The prescription of anti-platelet agents, beta-blockers, statins and angiotensin conversion enzyme-inhibitors (ACE-i) were also recorded.
Based upon the ACC/AHA 2005 Practice Guidelines for the management of patients with peripheral arterial disease and upon the IV Brazilian Guideline for Dyslipidemia and Atherosclerosis prevention from the Department of Atherosclerosis of the Brazilian Society of Cardiology, we defined six prevention goals that should be achieved by every patient: (1) systolic blood pressure <140mmHg, (2) diastolic blood pressure < 90mmHg, (3) LDL-chol < 100mg/dL, (4) HDL-chol > 40mg/dL for men and > 50mg/dL for women, (5) do not smoke and (6) practice of aerobic exercise. For diabetic patients, the goal for glycated hemoglobin was <7%. Considering that lipid profile and blood pressure should ideally be checked at least every 6 months, we defined as not achieving the blood pressure and/or lipid goals, patients who had not been tested in the past 2 years.
The medium number of goals achieved per patient was calculated and statistical analysis was performed to identify the factors that influenced it.

Statistical Analysis:

A descriptive analysis of the demographic and risk factors characteristics was initially performed for the entire cohort of patients and then we compared these characteristics between the vascular and the cardiology group. Variables were tested for normal distribution and the t-test was applied for the continuous variables (described as mean values and standard deviation) and the X² for categorical variables (described as percentage values), or, when variables did not pass in the normality test, the non-parametric equivalents were applied.
With the aim of identifying the predictors of a greater number of goals achieved by patient, we performed a series of univariate analyses and those variables with a previously assumed association to the independent factor (eg: gender) or those variables with a statistical significance level that reached a pre-defined P < 0.10, were included in a logistic regression model.
For all tests a probability value <0.05 (2-sided) was considered significant. All statistical analyses were performed using SPSS 17.0 statistical software.

Results

Between March and November of 2010, a total of 200 patients were analyzed, and eight of them were excluded for not having atherosclerosis as the primary cause for cardiovascular disease. From those who were enrolled at the study, 93 were selected from the vascular surgery clinic and 99 from the cardiology clinic. Nearly half of them were hospitalized (49%). Seventy-seven patients (40%) were women and 115 (60%) were men. Their average age was 65.66±10.50 years. The clinical manifestation of atherosclerotic disease was coronary artery disease for all cardiology patients and for vascular surgical patients it was aortic disease (aneurysm or dissection) in 50%, followed by peripheral artery disease in 22.6% and carotid obstruction in 20.4% of the cases. The remaining 7% were treated by vascular surgeons because of other atherosclerotic problems such as popliteal aneurysm or renovascular disease. We found that 59.9% were treated in two or more medical services.
According to patient`s information about their atherosclerotic risk factors, 77.6% had hypertension, 75% of them were sedentary, 65.7% were current or former smokers, 57.3% had dyslipidemia and 39.1% had diabetes. Although 70.8% of our patients have informed that they had received dietary advice, only 44.8% assumed having a balanced diet. As for aerobic exercise: 57,8% were encouraged to perform exercise but only 25% have informed to practice it in a regular basis. Regarding medical advice for smoking cessation, 65% of the current and former smokers informed they were encouraged to quit smoking by their physicians.
Regarding the prescription of protective medications, 91.1% of our patients were receiving statins, 87.5% were receiving aspirin (AAS), 67.2% beta-blockers, 54.7% angiotensin conversion enzyme inhibitor (ACEi) and 5.2% clopidogrel. Among those patients that had received some kind of medication prescription, 8.3% assumed that they did not take it regularly.
The 6 prevention goals defined for this study: (1) systolic blood pressure <140mmHg, (2) diastolic blood pressure < 90mmHg, (3) LDL-chol < 100mg/dL, (4) HDL-chol > 40mg/dL for men and > 50mg/dL for women, (5) do not smoke and (6) practice of aerobic exercise, were achieved in 57.3%, 67.2%, 40.1%, 27.6%, 88.5% and 25%, respectively. The average number of goals achieved by patient was 3.06±1.31. Among those patients that have diabetes, only 17.3% had glycated hemoglobin (HbA1C) < 7%.

When asked about the reason for being treated, 182 (94.8%) patients claimed knowing their disease, but when we compared the diagnosis reported by the patients with the diagnosis recorded by the physicians in medical charts, it was discordant for 24 patients (12%). When asked about the importance of cardiovascular prevention ( eg.:question for cardiology patients: Do you know that if you practice exercise, quit smoking, control your blood pressure and cholesterol levels, besides the benefits for your heart you can also prevent stroke and other vascular problems?), 22.9% answered that they were not aware of it.
The comparison of the demographic characteristics between vascular and cardiology patients is represented on table 1. We found that there were more diabetic patients in the cardiology group and that cardiology patients received dietary counseling more frequently than vascular patients. In the other hand, there were more current smokers among the vascular patients and they were more frequently treated by another physician. Besides, cardiology patient received more prescription of protective medications. We also found that patients from the vascular surgery demonstrated to have less knowledge about their health problem than cardiology patients, as the rate of discordance between the self reported and the medical diagnosis was greater in that group.
Twenty- two (23.6%) vascular patients and 14(14.1%) cardiology patients did not have laboratorial exams for the past 2 years and 46 (49.5%) vascular patients did not have blood pressure measurement, in contrast with the cardiology group, in which only 1 patient (1%) did not have blood pressure measurement. However, when comparing diabetes monitoring, namely glycated hemoglobin ((HbA1C), there is an inversion: 16% of the diabetics from vascular surgery did not have HbA1C measurement, while 30% of the diabetics in the cardiology group did not have this test for the past 2 years. The average values of blood pressure and lipid profile are displayed on table 1.
As represented on figure 1, except for the HDL-cholesterol goal, all the others goals were more frequently achieved by cardiology patients. There was a significant difference between the two groups regarding the average number of goals achieved by patient (vascular= 2.67 and cardiology= 3.40; P<0.005).

Percentage of cardiology and vascular surgical patients that achieved each goal (novo titulo para fig 1)

A series of univariate analyses were performed to determine the predictors that might contribute to a major number of goals achieved by patient (Table 2). Knowing the reason for treatment, reporting the right diagnosis, being inpatient, being from cardiology clinic, receiving the prescription of statin, receiving the prescription of acetylsalicylic acid and receving the prescription of β-blocker were the factors that contributed to a greater number of goals/patient.
Table 2. Univariate Analysis: Predictors of greater number of goals achieved by patient
p value
Male gender 0.105
Age ≥50 0.149
Diabetes 0.188
Dyslipidemia 0.392
High blood pressure 0.321
Inpatient <0.0001
Patient from Cardiology <0.0001
Being treated by another physician 0.687
Awareness about the importance of secondary prevention 0.264
Knowledge of reason for treatment 0.001
Reporting the right diagnosis 0.005
Reporting that follows the medical prescription 0.430
Physician's aerobic exercise advice 0.080
Physician's dietary counseling 0.528
Prescription of Acetylsalicylic acid 0.016
Prescription of Statin <0.0001
Prescription of β-blocker <0.0001
Prescription of ACE inhibitors 0.320

Although the gender did not show a relevant statistic p value (p=0.105) it was included in the multivariate analysis (Table 3), because in previous studies it was clearly associated to better prevention. (Hirsh- Circulation 2007)
The variables “knowledge of reason for treatment” and “reporting the right diagnosis” were both significantly associated to our independent variable, but considering their collinearity, we decided to include in the linear regression model just one of them.
According to the multivariate analysis, the independent predictors that contributed to higher number of goals/patient identified were: Male gender, being inpatient, being from cardiology clinic, knowing the reason for treatment and receiving prescription of β-blocker.

Table 3. Independent factors associated with more goals achieved. Results from the linear regression analysis:
p value
Male gender 0.011
Inpatient <0.0001
Patient from Cardiology 0.011
Knowledge of reason for treatment 0.028
Physician's aerobic exercise advice 0.104
Prescription of Acetylsalicylic acid 0.334
Prescription of Statin 0.296
Prescription of β-blocker 0.011
Discussion

In our cohort of patients, not surprisingly, the prevalence of traditional risk factors was high but similar to other international cohorts already published in the literature; for example our 77.6% hypertension rate fits in the range from 46% up to 82.5% found in other 7 studies that included patients with atherosclerosis (Loyd, Deepak, Rehring, Blacher, McDermott, Kinikini, Zeymer). Those findings reinforce the great opportunity to implement the secondary prevention measures in our high risk population.
Although it is well recognized that lifestyle modification is one of the most important interventions for cardiovascular risk reduction, it is often neglected and less translated into clinical practice than medication prescription (Flu, McDermott, Kinikini). In the present study we found that only only 44.8% of our patients assumed having a balanced diet and only 25% practiced exercise in a regular basis. The poor adherence of the patients to prescription usually is the first factor considered to justify gaps between theory and practice, but in our study we found that physicians adherence to guidelines recommendations comes first, as exclusively 70.8% of our patients have informed that they had received dietary advice and only 57.85% were encouraged by their physicians to do physical exercises. Regarding medical advice for smoking cessation, 65% of the current and former smokers informed they were encouraged to quit smoking by their physicians and the 11.6% rate of current smokers in our entire population, although not ideal, can be considered below the smoking prevalence in other populations with atherosclerotic disease ( 22% Mc Dermott to 44% Blocher in patients with PAD). We must consider that a limitation of this study regarding the reliability of this information is the fact that physicians advice about lifestyle can be underestimated because it was indirectly evaluated by patients information.
The prescription of medications that improve secondary prevention showed better results. If we consider that antiplatelet therapy is the only medication that should be prescribed for every patients included in our study, unless contra-indications were present, the 87.5% aspirin (AAS) added to the 5.2% clopidogrel prescription rate is very good. Statins were prescribed to 91.1% of our patients, 67.2% of them were under beta-blocker therapy and 54.7% received angiotensin conversion enzyme inhibitor (ACEi). Considering that more than 70% of our patients had hypertension and systolic blood pressure levels were not well controlled in almost 43% of our patients, the ACEi and beta-blockers certainly are underused and probably there is also a dose titration inadequacy. The same concern is applicable to lipid control; despite 91.1% of our patients received statin therapy, only 40.1% had LDL-col level below 100mg/dL. The 8.3% rate of poor adherence to medication prescription can also contribute to the lack of efficacy in achieving the desired blood pressure and lipid levels, and it is probably underestimated, as our exclusive source of information about this data is the patient answer when interviewed.
Despite our reality is far from ideal, it is equal or even better than registries in the literature. In the biggest systematic review about secondary prevention measures for patients with PAD published by Flu et al in 2010, from 671 analyzed patients with PAD, only 23% were prescribed for walking exercise (Flu) and 39% of 1.963 current smokers patients received smoking cessation advice. We could not find published data about dietary advice for this specific population. Regarding medication prescription, from 34.157 patients, only 63% received antiplatelet agents and only 45% received lipid lowering medications. The authors found a hypertension prevalence of 73%, but only 46% of the patients were under anti-hypertensive medication therapy.

Although the percentage of patients in use of antiplateles and statins is satisfatory, the number of goals achieved is far from the expected. This suboptimal tratment is, however, shown in other studies. Kinikini et al., in 2006, published a study in which 200 patients pf the University od Utah Vascular Surgery clinic wew
of Utah Vascular Surgery clinic NUMERO METAS/ PACIENTE falar um pouco da decepção dos nossos resultados e traçar paralelo com outros estudos descrever trabalho/ resultados Kinikini.

We found that patients from cardiology clinic achieve more goals than patients from vascular surgery clinic. Comparing the demographic characteristics from both clinics, we noticed that the patient’s knowledge regarding the disease is greater in cardiology group. Previous study also suggests that patients with peripheral arterial disease underestimate their risks regarding cardiovascular events1. The fact that coronary diseases are more often shown by media and consequently more well-known by the general population than peripheral arterial disease is one of the possible explanation for this finding. Another difference between cardiology and vascular surgery clinics is the lower prescription of medication for secondary prevention by the second clinic. This finding is also observed in literature2. Patient from vascular surgery are more assisted by another physician, which can result in lack of responsibility by the vascular physician. (DEIXAR CLARO QUE ESTES FATORES PODEM CONTRIBUIR MAS NÃO EXPLICAR DEFNITIVAMENTE POIS A DIFERENÇA VASC E INCOR PERSISTE NA MULTIVARIADA... se estes fatores justificassem por completo na análise multivariada não haveria mais significância)
When demographic characteristics of inpatients and outpatients were analyzed we observed that they are a homogenic population with resembling age, gender, risk factors, etc. However, the use of statin (p=0.009) and being treated by another physician (p=0.027) are more frequent in inpatients. The significant difference in the use of statin is probably a consequence of vascular guidelines that recommend the prescription of statin to those patients as it reduces cardiovascular risks in the perioperative period.
Furthermore, inpatients have better systolic and diastolic blood pressure levels, too (129.77±21.39 vs 121.10±20.14 p=0.016 ; 79.79±12.80 vs 69.85±11.49 p<0.0001) . The difference between those blood pressure levels could be explained by the fact that inpatients are not influenced by the presence of health professionals since they are in contact to them almost all the time. Consequently inpatients do not stay apprehensive when their blood pressure is measured. Besides, inpatients are normally adhered to a medical treatment, since they are assisted from the health professionals intensively.
Another reason that could justify the achievement of better blood pressure levels in inpatients is not only that being hospitalized is a condition of turbulent motion so that inpatients normally collaborate with any medical conduct, but also and mainly because the physician-patient relationship is qualitative and quantitative better established as both have more time to dedicate to each other.
It is important to mention that many outpatients did not achieve goals because they did not have their datas collected, e.g. 45 outpatients did not have their blood pressure measured to only 2 inpatients. However, the main values obtained were not satisfactory in both of them, but it is worst in outpatients.
Knowing the reason for treatment was identified as a predictor of better secondary prevention in all patients. Previous studies show that patients with peripheral arterial disease (PAD) are less informed about their condition if compared with patients with coronary arterial disease (CAD)1,(apos citar, fazer um mini abstract) so that PAD patients underrecognize the high risk of cardiovascular and mortality associated with their condition compared with CAD patients. (enfatizar que ambos pacientes estao mal informados)It shows that PAD patients are not aware about the importance of the secondary cardiovascular prevention. A recent study revealed that patients with PAD receive knowledge of this condition from media, such as television and magazines, friends or family members. Only a small fraction of individuals received information from physicians (14%), nurse (2%) or pharmacist (0.2%)3. These results demonstrate that health professionals do not provide educational resources to the patients, so that they are not well informed about their condition. Besides, establishing a diagnosis is not always linked to disease awareness, as a previous study showed that individuals with an established PAD diagnosis are not very aware of the influence of glicemic blood levels on the disease3. It leads us to think that informing the patient about the disease may be or may be not linked to relevant clinical outcomes, depending on whether useful knowledge is transferred to the patient such as secondary cardiovascular prevention.
In addition, since patients have access to health care information they are increasingly influencing their prescription of preventive practices, so that they can discuss about the disease they have with their physician resulting in better knowledge and comprehension. As CAD is more often broached on media, individuals with CAD are better well informed and also better treated. However, it is important to be clear that physician’s orientations are indispensable and they can not depend on media in no way.

References:
knowledge and attitudes…
international prevalence…
gaps in public knowledge…