A MEDLINE search was performed for studies of dietary quality after CHD diagnosis (January 2005 to December 2009). The following keywords were used in combination: ‘diet’, ‘dietary quality’, ‘dietary patterns’, ‘adherence’, ‘coronary heart disease’ and ‘cardiovascular disease’. Few studies have examined dietary quality after CHD diagnosis. Patients who participated in the Prospective Registry Evaluating Myocardial Infarction: Events and Recovery (PREMIER) health status study (n
= 2498)were evaluated for adherence to diet, smoking cessation, weight loss, and cardiac rehabilitation. Adherence was determined from the medical records by recording which of these instructions were documented as being provided to patients at discharge and 1 month post discharge, and how well they had followed these instructions. Fewer than half recalled receiving any advice about cholesterol management, or weight loss [8••
]. One month after discharge, only 51% of patients self-reported that they were ‘adherent’ to dietary instructions, 43% to weight loss, and 33% to cardiac rehabilitation. A detailed dietary measure or questions regarding the specific diet that was advised were not used in this study.
A Swedish case–control study of post-myocardial infarction (MI) patients (525 cases, and 1890 controls without a history of MI) and their diets indicated that total fat and saturated fat intakes were lower in cases than in controls, whereas intakes of carbohydrate and protein were higher in cases than in controls [9
]. The study also indicated that levels of several micronutrients, such as ascorbic acid, folate, fiber, and vitamin E, were higher in cases than in controls.
Murphy et al
] examined changes in women’s total dietary fat intake following an acute cardiac event, evaluating consecutive admissions of 239 women aged 36–84 years to four hospitals at the time of an acute event in Australia. Total fat intake decreased substantially during the first 2 months following hospitalization, and then increased over the subsequent 10 months. By 12 months, total fat intake remained significantly lower than at baseline. Baseline interviews were conducted in hospital 4–8 days following admission, and pre-event measures were not available. The investigators suggested that future studies investigate options for assisting patients to sustain dietary changes, with special concern for older patients and those with hypertension, who showed less reduction in total fat intake. A Short Fat Questionnaire (SFQ) [11
] was used to measure total fat intake in this study, so changes in saturated or trans fat, or any other AHA recommendations, could not be determined.
We measured the diet quality of 555 CHD patients using 24-h diet recall 1 year after diagnostic coronary angiography [12
]. Using the Alternative Health Eating Index (AHEI) [13
] to assess diet quality, we found that a high proportion of those patients had not made the necessary improvements to their diets to help reduce the risk of a secondary CHD event. Of a maximum 80 points – which indicates the healthiest diet – the average AHEI score was 30.8. When AHEI components were examined, only 12.4% of the participants met the optimal daily consumption of vegetables (does not include potatoes) and 7.8% for fruit. Only 8% of the patients met the cereal fiber recommendation, and only 5.2% of the participants limited their trans fat intake to 0.5% of total calories or less. In addition, nearly 11% of calories were from saturated fat (less than 7% is recommended), whereas total fiber was only 16.8 g per day (25 g or more per day is recommended). Similarly to our study, Andersen et al
] examined dietary quality in 116 Norwegian patients with CHD. A self-administered food frequency questionnaire (FFQ) was used to assess diet. Using a similar score of AHEI (with same questions), they found that 91.3% of the participants had a suboptimal diet quality. Since dietary quality has been shown to be associated with cardiovascular outcomes [13
], the improvement of dietary quality should reduce CHD recurrence. These studies suggest significant room for improvement in dietary quality for secondary prevention of CHD.
Using a prospective cohort study design, Twardella et al
] examined long-term adherence to dietary recommendations with a cohort of 1206 patients in Germany undergoing inpatient rehabilitation after an acute manifestation of CHD. Dietary intake was collected before, during, and 1 and 3 years after rehabilitation using a FFQ [16
]. A nutritional index was used to measure dietary quality, which was developed using the recommendations made by nutritional associations in Germany and was the basis for the meals served in the rehabilitation clinics. The index emphasized a balanced diet of meat and low-fat foods, high intake of fruits, vegetables, and wholemeal bread, and avoidance of eggs, cream, sugar-rich foods, salty snacks, French fries (chips), and convenience foods, which is similar to the AHEI. They found that intake of recommended food items such as low-fat sausage, margarine, and wholemeal was increased after rehabilitation compared with the year before rehabilitation, whereas the intake of high-fat and not recommended food items such as French fries, milk, eggs, white bread, and cake was decreased. However, 1 and 3 years after rehabilitation these improvements were only partially maintained.
In the United States, roughly 80% of CHD patients do not attend cardiac rehabilitation programs. Using Medicare claim data, Suaya et al
] reported that only 50 000 (18.7%) of 267 427 Medicare-eligible patients above 65 years of age who experienced a CHD event participated in a cardiac rehabilitation program. Low participation rate was associated with the following characteristics including: older age (>85), female sex, nonwhite racial/ethnic status, lower socioeconomic status, significant comorbid conditions, and long distance from the patient’s home to a cardiac rehabilitation center. In addition, current policies specify that, for patients to participate in a cardiac rehabilitation program, they must be referred by their healthcare provider. Because of competing demands on their time and attention, many clinicians may not remember to refer their patients to a cardiac rehabilitation program. A systematic review of 10 published observational studies (1999–2004) [18
] found that referral rates to cardiac rehabilitation ranged from 10 to 60%, and the mean referral rate was approximately 34%. However, attendance at cardiac rehabilitation, after referral, was less than 50% in almost all of the studies.