Knowledge and Implementation of Cardiovascular Risk Clinical Practice Guidelines by General Practitioners and Specialists

INTRODUCTION

The prevention of cardiovascular disease is among the most profitable of all medical interventions.¹ However, it would seem that vascular protection drugs are not used to their full potential.² Further, the control objectives relating to widely accepted biological risks seem only to be met in a small proportion of patients. For example, the percentage of people with high blood pressure (HBP) who receive treatment for this problem in Spain is only approximately 13%-36%­meaning that in approximately 70% of these subjects the recommended blood pressure is never attained.³ In addition, the control of fasting glucose in approximately 40% of treated diabetics in Spain is poor.^4,5 The figures reported for Europe⁶ and the USA⁷ are similar.

The ACORISC registry was designed with the aim of systematically analyzing the extent to which normal clinical practice meets the recommendations of the best known clinical practice guidelines (CPG)^8-19 regarding the pharmacological treatment of high vascular risk patients. The objectives were to determine the degree of knowledge and use of these guidelines by medical professionals attending high vascular risk patients, and to establish the degree of control of the most important risk factors, such as HBP and diabetes mellitus (DM).

METHODS

The registry involved the participation of 384 doctors (84% of those originally invited to participate) who attended patients at primary care centers (n=236) or at specialist centers (usually cardiologists but also some endocrinologists) (n=148) throughout Spain. These doctors were selected by the boards of professional cardiology and primary care societies. All were explained how to record the data required in a meeting prior to the start of the study. The data of consecutive patients between 1 February and 30 April 2005 were collected in an open, cross-sectional manner.

Patients and Data Included

Patient demographic, clinical and analytical data were recorded in a single database (which did not identify them neither personally nor officially). All patients had either been previously diagnosed, or were diagnosed at the moment of inclusion, with the following problems: type 2 DM (according to the criteria of the American Diabetes Association),⁸ essential HBP (according to the criteria of the European Society of Cardiology/European Society of Hypertension joint committee),⁹ or chronic ischemic heart disease (angina with ischemia or significant and documented coronary heart disease, demonstrated infarction, or prior revascularization). All patients gave their consent to be included; none were originally excluded The study was approved by the Galician Research Committee. In addition, the doctors were asked to complete a questionnaire indicating the different CPG^10-19 they knew of, the extent of their knowledge of these guidelines (1: little, 5: maximum), and which they used when treating the above high vascular risk patients.

Data Analysis

To examine the degree of control of cardiovascular risk factors, the percentage of patients receiving inadequate control was determined according to the following criteria (taken from the CPG being used)^8-11,13: systolic blood pressure ≥130 mm Hg and/or diastolic blood pressure ≥80 mm Hg, low density lipoprotein cholesterol (LDL cholesterol) or high density lipoprotein cholesterol (HDL cholesterol) ≥130 and ≤40 mg/dL respectively, baseline glycemia ≥126 mg/dL or hemoglobin A_1c>7% in known diabetics, baseline glycemia ≥110 mg/dL in non-diabetics, excess body weight (body mass index >25), microalbuminuria (>30 mg/24 h), and use of tobacco.

The overall treatment of each patient was recorded as follows: "adequate" if at least one of the drugs prescribed was indicated and there were no contraindications, "intermediate" if the profile of drugs prescribed was neutral or indifferent, and "inadequate" if any prescribed drug was contraindicated. For this, the absolute indications, possible indications and contraindications of four widely used CPG (those of the VII Joint National Committee [US] on high blood pressure [JNC VII]¹⁰, the Plan Integral de Cardiopatía Isquémica [PICI] of the Spanish Ministry of Health,¹² the Guías para el Tratamiento de la Diabetes de Tipo 2 en la Atención Primaria [GEDAPS],¹⁸ and the Guía de Prevención Cardiovascular en Atención Primaria [semFYC-PAPPS, 2003])¹⁹ were consulted regarding the following agents: thiazides, alpha-blockers, nitrates, beta-blockers, angiotensin converting enzyme inhibitors (ACE inhibitors), statins, fibrates, thiazolidinediones, secretagogues, biguanides, and alpha glycosidase inhibitors.

Statistical Analysis

Continuous variables were expressed in terms of central tendency and spread (mean and standard deviation [SD] or median and interquartile range); discrete variables were expressed using frequency tables. Categorical variables were analyzed by the χ² test. Normally distributed continuous variables were compared using the Student t test or by ANOVA; non-normally distributed variables were analyzed by the Wilcoxon test. The Kruskal-Wallis test was used for the comparison of more than 2 samples.

RESULTS

Risk Factors

The final patient population analyzed included 5849 subjects (66% of the those originally included: the remainder were excluded from the analysis for failure to meet all necessary conditions). Of these, 92% had HBP, 54% had DM, and 46% had chronic ischemic heart disease (or their combinations: 40.3% had 2 of these problems while 26.2% had all 3). The mean age of the patients was 65±11 years; 52.8% were men. The mean body mass index was 28.5±4.6. The mean blood pressure was 142±17/82±11 mm Hg. Other risk factors present were: use of tobacco (26.3%), hypercholesterolemia (47.6%), obesity (32%), a family history of early premature heart disease (27.7%), left ventricular hypertrophy (34.8%), kidney dysfunction (8.3%), peripheral arterial disease (11.5%), proteinuria (12.9%), and atrial fibrillation (11%). Table 1 summarizes the values of the biological variables analyzed.

Knowledge and Use of Guidelines

Table 2 shows the results regarding the knowledge and the use of the different guidelines for the treatment of HBP, DM, and overall cardiovascular risk, by the doctors in primary and specialized health care.

Treatments

Therapeutic measures of vascular protection were on prescribed in 7% of the patients were not prescribed vascular protection treatment. Anti-hypertension drugs were prescribed in 88% (65.1% took ACE inhibitors, 22.6% took diuretics, 14.7% took calcium antagonists, and 13.5% took beta-blockers). Anti-platelet drugs were taken by 34% of the patients, anti-diabetes agents by 36% (20% took sulfonylureas and 15% biguanides), and statins by 41.4%.

Treatment was considered adequate in 80.9% of cases, inadequate in 14%, and intermediate in 5.1%. According to the different folowed, there was a contrandication in 2.9% of treatments with angiotensin II receptor antagonists, 3.1% of treatments with beta-blockers, 3% of treatments with ACE inhibitors, 38% with sulfonylureas, 1% with alpha glycosidase, and 33% of treatments with biguanides were contraindicated. Treatment with biguanides was contraindicated due to a patient history of heart (14%) or kidney (10%) failure; treatment with sulfonylureas was contraindicated because of kidney (32%) or liver (10%) failure.

In 48% of patients with DM plus HBP, or chronic ischemic heart disease plus DM or HBP. ACE inhibitors were not prescribed which, according to the CPG, are absolutely indicated.

Control of Risk Factors

High blood pressure was observed in 87% of patients, 79% were overweight, and 61% had hypercholesterolemia. Figure shows the degree of control of the different risk factors in patients with DM, HBP, and ischemic heart. Table 3 shows the percentage inadequate control of the different risk factors in patients with combined disease.

DISCUSSION

Knowledge of and Use of Clinical Practice Guidelines

This study analyzed the degree of knowledge and use of CPG in the prevention of cardiovascular disease by different medical professionals around Spain. Although numerous studies have examined the prevalence of risk factors,^20-22 fewer have looked into how well they are controlled in Spain.^3-5,23,24 The results are similar to those obtained in countries of comparable culture.^6,7,25,26

In the chain of transmission from CPG to patient, there can be no doubt that the first link involves medical professionals knowing these guidelines. Among the present doctors providing primary and specialized care, the level of knowledge of the major CPG can be described as acceptable; on the increasing semi-quantitative knowledge scale used (1­5), these medical professionals declared a high grade (≥3) of knowledge. This implies knowledge of risk detection procedures and the control objectives for the different biological variables that influence them. The lack of definition of these,²⁷ however, is a clear barrier to the use of CPG.²⁸ The second step involves the use of these CPG with patients. The present results showed the logical use by primary care doctors of more local CPG produced by scientific societies more closely related to their field of medical practice, while specialists tended to use the CPG of specialized national or international scientific societies.

Quality of Preventive Treatment

Compliance with CPG is essential if treatments are to be correctly administered.^29,30 However, it is not enough that doctors simply declare knowledge of these guidelines in questionnaires; despite their encouraging voluntary declarations regarding their knowledge and use of these guidelines with high risk (those with DM or HBP) and very high risk patients (those with chronic ischemic heart disease), the actual results recorded were rather less optimistic. The percentage of patients with these degrees of cardiovascular risk that were well controlled according to the CPG was low (Figure)­and it is little consolation that similar results are found in other countries culturally comparable to Spain and with a similarly advanced health system.^25,31,32 Rather, these results lead to the question on how to fill the gap between the content of CPG and the proper use of these documents with patients. Automatic, computer-generated recall systems do not seem to be very successful.³³ Rather, reiterative, interactive, multidisciplinary, and comprehensive campaigns seem to achieve better results.^34,35

Figure 1. Percentage inadequate control of risk markers. LDL-C indicates, low density lipoprotein cholesterol; HDL-C, high density lipoprotein cholesterol; Glyc/Hb, glycemia or glycosylated hemoglobin; BMI, body mass index; MA, microalbuminuria; BP, blood pressure; Tob, use of tobacco.

An often cited example of the poor use of CPG is the prescription rate for ACE inhibitors in patients with chronic ischemic heart disease or DM plus another risk factor.^36-38 In the present study, only half the patients for whom these drugs were theoretically indicated by the CPG were actually prescribed them.

The fact that the majority of non-indicated treatments involved oral anti-diabetes agents suggests that the CPG were neither that well known nor properly applied. These drugs, which until recently were prescribed only by specialists, should be the focus of special training programs since they are increasingly in demand and have to be prescribed by numerous and different professionals who treat patients with DM.

Limitations of the Study

There is no doubt that the self-esteem of respondents introduces bias into replies to questionnaires. However, the homogeneity of the present results suggests that, if such a bias exists, it was probably uniformly distributed. Attempts to prevent selection bias were made by insisting upon the participating doctors that they included all the patients they saw. The group of primary care doctors was homogeneous, but not that of the specialists, who were normally but not always cardiologists. The selection of these professionals was not randomized and it is difficult to tell if the desire to participate reinforces or limits the conclusions that can be drawn.

CONCLUSIONS

The primary care and specialist doctors that participated in the present study, all of whom attended high cardiovascular risk patients, showed an acceptable knowledge of current CPG. However, there were differences in the choice of guidelines used according to the type of work undertaken by the different physicians. For hypertension, the JNC-VII guidelines were those most used by specialists, while in the primary care setting the semFYC guidelines were those most used. With respect to diabetes, both the primary care and specialist doctors preferred the GEDAPS guidelines. For patients with ischemic heart disease, the specialists most commonly used the ACC/AHA guidelines, while the primary care doctors used the semFYC-PAPPS guidelines. These differences would seem to be logical and unavoidable, and are most probably the cause of deficiencies in the control of risk factors.

The results show that is clearly room for improvement in the management of high/very high vascular risk patients, especially with respect to the control of hypertension, obesity and dyslipidemia which affected two thirds of the patient population studied. Adequate control of biological variables such as blood pressure, the LDL cholesterol level, and glycemia, etc was particularly lacking in patients with combined disease. There is a need to increase the awareness of both doctors and patients regarding the importance of prevention and the continuous analysis of the performance of any measures adopted via studies such as the present.

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This work was funded by Sanofi-Aventis. The funding body was not involved in the organization or management of the study nor was it involved in the analysis of the results, which were examined by an independent committee.

Correspondence: Dr. E. Alegría Ezquerra.
Departamento de Cardiología y Cirugía Cardiovascular. Clínica Universitaria de Navarra.
Avda. Pío XII, s/n. 31008 Pamplona. Navarra. España.
E-mail: [e-mail]

Received December 23, 2005.
Accepted for publication May 11, 2006.