CARdiac Disfunction In Obesity * Early Signs Evaluation

Obesity is one of the most important public health problems in the Western
world. In The Netherlands more than 50% of the people between 30 and 70 years
is overweight (a BMI of * 25 kg/m2). In14 percent there is even severe
overweight (obesity, or a BMI of * 30 kg/m2). Also, the prevalence of heart
failure is increasing. Nowadays, almost 30% of Dutch people will develop heart
failure in his/her life.
Obesity increases the risk of developing diabetes mellitus, dyslipidemia and
hypertension, all risk factors for the onset of heart failure. Obesity itself
is also an independent risk factor for development of heart failure, but this
so-called "obesity cardiomyopathy" is still insufficiently recognized.
In view of the increasing prevalence of both obesity and heart failure, an
important growing overlap of these two clinical entities in the near future is
expected. There is currently not enough knowledge about the role of obesity in
causing cardiac dysfunction. This impedes adequate risk stratification and
treatment of the obese patient.

Objective with respect to patient care:
Obese patients have an increased risk of developing heart failure. By gaining
insight on the role of obesity in cardiac dysfunction it will be possible to
provide a better risk stratification for the onset of heart failure in obese
patients. One of the important goals of the research is to identify parameters
that at a very early stage are able to show cardiac dysfunction in patients
with obesity. The aim will be to prevent heart failure in such high-risk
patients through stricter lifestyle interventions and follow-up, possibly
bariatric surgery and eventually a more patient-specific drug treatment.

Objective with respect to health care at the population level:
To diseases due to overweight 1.6 billion Euro in 2012 was issued. The most
money was spent on heart disease. By allowing heart failure in obese patients
to be better diagnosed and treated, these costs can potentially be brought down
significantly.

Objective with respect to the working process of the attending physician:
The value of history and physical examination are limited in excluding or
demonstration of heart failure in a patient with obesity. Symptoms (fatigue,
dyspnea) and abnormalities on physical examination (edema, increased waist
size) can both be caused by obesity and heart failure. Furthermore, biomarkers
for heart failure (for example, the natriuretic peptides) can be falsely
reduced. The research aims to identify better parameters for determining
cardiac dysfunction in patients with obesity.

The CARDIOBESE study is a combination of both a cross sectional study of
obesity patients and age and gender matched healthy controls (primary
objective), and a prospective follow-up study of obesity patients undergoing
bariatric surgery (secondary objective).

(Primary objective) During one year, prospective inclusion of 100 consecutive
obesity patients that undergo bariatric surgery will take place at the
Franciscus Gasthuis and Maasstad Ziekenhuis. By means of conventional and
advanced echocardiography, laboratory tests, and heart rhythm registration
early signs of cardiac dysfunction will be studied. Baseline data of the
obesity patients will be compared with a healthy, age- and gender-matched,
control group (50 subjects).

(Secondary objective) Associations of cardiac dysfunction with obesity related
characteristics (e.g. markers of inflammation, lipids, presence of diabetes)
will be investigated. Also, in the obesity patients, the impact of bariatric
surgery, and related metabolic changes, on (changes in) cardiac dysfunction
will be studied by repeating the tests one year after bariatric surgery. A
longitudinal study design is an optimal design to study the intra-personal
impact of obesity and bariatric surgery related changes on changes in cardiac
dysfunction.

The burden for patients participating in this study is relatively low. Patients
do not have to make extra visits to the hospital, do not have to undergo extra
invasive tests, and treatment of the patients will not be changed or delayed.
Nevertheless, patients do have to undergo some extra tests. However, the
echocardiogram and holter monitor are harmless and the blood samples will be
taken from a venapunction that will be performed anyway (for clinical reasons).
Yet, for the study 5 extra tubes will be collected (total 22 ml) at both
visits. Also, the controls do have to come to the hospital specially for the
study and for them the venapunction is performed solely for the study.

In general, patients and controls will not be informed about the results of the
diagnostic tests performed because of participation in the study. This because
the vast majority of the results of these tests does not have any known
clinical value. However, when there is an unexpected finding that does have
clinical relevance (e.g. significant valvular disease or decreased left
ventricular ejection fraction) the patient will be informed.

Since obesity is one of the most important public health problems in the
Western world and the prevalence of heart failure is increasing, the risk to
and burden for the subjects will be in proportion to the potential value of the
research.