With increasing life expectancy, cardiac surgical procedures are increasingly being performed in older adults. The biological syndrome of frailty is an aging-associated state with diminished physiological reserve and resistance to stressors, such as major surgery. In the European System for Cardiac Operative risk Evaluation (EuroSCORE II) and the Society of Thoracic Surgeons (STS) risk scoring systems, patient comorbidities including advanced age and poor mobility are considered as risk factors for operative mortality. However, an objective assessment of frailty is not included. Traditionally, frailty assessment before cardiac surgery is primarily performed based on surgeon's subjective perception of patient's general appearance. Objective measurement of frailty is increasingly being applied as a routine part of preoperative evaluation of elderly patients undergoing cardiac surgery. The most widely used frailty assessment tool is the Fried scale. The investigators aim to investigate whether Fried scale would predict operative mortality and morbidity in elderly patients undergoing elective cardiac surgery.

Consecutive patients who are scheduled to undergo elective cardiac surgery in Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital will be evaluated for enrollment. Those who meet inclusion and exclusion criteria will be invited to be study participants. Volunteers will constitute the study population. All participants will undergo routine preoperative risk assessment procedures of our institution, which include history, physical examination, blood chemistry, chest X-ray, echocardiogram, and spirometry. As part of this routine assessment, Fried scale (5-meter walk test, hand-grip strength, questioning of weight loss, short version of the Center for Epidemiological Studies-Depression scale, and short version of the Minnesota Leisure Time Physical Activity questionnaire) will be applied to all participants. Demographics characteristics and clinical data will be observed and recorded. Participants will be divided into 3 groups according to Fried scale; frail, moderately frail, and not frail.

In order to investigate the ability of Fried scale to predict cardiac operative mortality and morbidity, groups will be compared in terms of surgical mortality, renal failure, stroke, prolonged mechanical ventilation, deep sternal wound infections, re-operation, prolonged length of stay, and readmission rates.

Power analysis was performed to estimate sample size using G*Power (v3.1.7) software. A total 150 participants are needed in order to achieve an 80% (Beta=0.2) power at the 5% (Alpha=0.05) level of significance.

Categorical data will be presented as frequency and percentage. Continuous variables will be presented as mean [±standard deviation] and median [interquartile range]. Categorical variables will be compared using chi-square and Fisher's exact tests. Kolmogorov-Smirnov test will be used to assess distribution of continuous variables. Continuous variables with a normal distribution will be compared using Student's t-test, and those with a non-normal distribution will be compared using Mann-Whitney U test.

SPSS for Windows v.17.0 (SPSS Statistics Inc., Chicago, Ill., USA) will be used for all statistical analyses. A two-sided p value of <0.05 will be considered to be statistically significant.

Inclusion Criteria:

• Age≥65 years
• Planned elective cardiac surgery

Exclusion Criteria:

• Age<65 years
• Emergent procedure
• Refusal to participate
• Clinical instability (recent myocardial infarction, decompensated cardiac failure, acutely symptomatic participants, abnormal vital signs)
• Canadian Cardiovascular Society grade IV angina pectoris
• New York Heart Association class IV heart failure
• Failure to cooperate due to neuropsychiatric disorders

Patients scheduled to undergo elective cardiac surgery in Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital