Minnesota leisure time physical activity questionnaire as an additional tool in clinical assessment of patients with coronary artery disease treated with angioplasty

Nowak Zbigniew; Nowak Agata

MINNESOTA LEISURE TIME PHYSICAL ACTIVITY QUESTIONNAIRE AS AN ADDITIONAL TOOL IN CLINICAL ASSESSMENT OF PATIENTS WITH CORONARY ARTERY DISEASE TREATED WITH ANGIOPLASTY

Zbigniew Nowak, Agata Nowak

Out of many methods used for assessment of physical activity, a questionnaire seems to be a simple and affordable method of assessing the risk of occurrence of coronary insufficiency. However the number of clinical studies done on the application of physical activity questionnaires is limited.

Aim. The objective of the present study was to analyze the suitability of Minnesota Leisure Time Physical Activity Questionnaire (MLTPAQ) in assessment of physical activity in patients after percutaneous coronary intervention (PCI) Material and methods. Design: prospective analysis — before and 6 months after PCI and correlation between level of physical activity and physical capacity assessed with treadmill exercise test (ET), ejection fraction (LVEF%) Setting: Upper Silesia Medical Center. Department of cardiology. Population: One hundred fiftieth four inpatients (mean of 56 y), among which there were patients with acute myocardial infarction (MI), with history of past MI and with IHD without MI. All subjects underwent coronarography procedure with optional PCI. All patients underwent phase I and II cardiac rehabilitation. The MLTPAQ was administered to all patients at the time of PCI and then 6 months later, so was the treadmill stress test (TST) and echocardiography (ECHO). Results. Total energy expenditure calculated with the MLTPAQ remained at the same level and was of low intensity (<4 MET <2000 kcal/week) 6 months after the PCI. There was an increased physical capacity noted 6 months after initial PCI: increased metabolic cost (MET); maximal oxygen consumption (VO2max); maximal heart rate (HRmax) obtained during the TST and decreased resting heart rate (HRrest). ECHO examination showed improved LVEF%.

Clinical Rehabilitation Impact: the helpfulness of the research may be used in the work of cardiologists or physiotherapists. The research will allow to estimate the actual level of physical activity and physical endurance of patients that were treated by angioplasty. Moreover, this is the simple and cheap method of estimation.

Conclusion. Despite increased physical capacity and improved heart hemodynamic resulting most likely from PCI procedure, patients presented with similar level of leisure time physical activity 6 months after the PCI.

Russ J Cardiol 2014, 4 (108), Engl.: 54-59

Key words: ischemic heart disease, percutaneous coronary intervention, physical activity questionnaire, treadmill stress test, echocardiography.

Academy of Physical Education, Faculty of Physiotherapy Katowice, Poland.

Corresponding author. Zbigniew Nowak Prof, PhD, Academy of Physical Education, Faculty of Physiotherapy, Mikolowska Str.72B, 40-065 Katowice, Poland, Tel: +48 32 207 53 01, Fax: +48 32 251 10 97, e-mail zbinow@gmail.com

CAD — coronary artery disease, ET — exercise test, HA — household activity, IHD — ischemic heart disease, LVEF% — left ventricular ejection fraction, LVESD — left ventricular end-systolic diameter, MET — increased metabolic cost, MI — myocardial infarction, MLTPAQ — Minnesota Leisure Time Physical Activity Questionnaire, PCI — percutaneous coronary intervention, RA — recreational activity, TST — treadmill stress test.

Received September 04, 2013. Revision received September 24, 2013. Accepted October 01, 2013.

МИННЕСОТСКИЙ ОПРОСНИК ФИЗИЧЕСКОЙ АКТИВНОСТИ В КАЧЕСТВЕ ДОПОЛНИТЕЛЬНОГО ИНСТРУМЕНТА ДЛЯ КЛИНИЧЕСКОЙ ОЦЕНКИ ПАЦИЕНТОВ С ИШЕМИЧЕСКОЙ БОЛЕЗНЬЮ СЕРДЦА ПОСЛЕ АНГИОПЛАСТИКИ

Zbigniew Nowak, Agata Nowak

Из многих методов, используемых для оценки физической активности, анкеты кажутся простым и недорогим методом оценки риска возникновения коронарной недостаточности. Однако количество клинических исследований, проведенных на применении анкетирования физической активности анкет, ограничено. Цель. Целью настоящего исследования был анализ пригодности Миннесот-ского опросника физической активности (MLTPAQ) в оценке физической активности пациентов после чрескожного коронарного вмешательства (ЧКВ) Материал и методы. Дизайн: перспективное исследование — до и через 6 месяцев после ЧКВ и корреляция между уровнем физической активности и физической способности, оцениваемой с помощью тредмил-теста с физической нагрузкой (ТТ), фракции выброса (ФВ ЛЖ%). Выполнено: в Медицинском центре Верхней Силезии, отделение кардиологии. Пациенты: 154 пациента в стационаре (средний возраст 56 лет), среди которых были пациенты с острым инфарктом миокарда (ИМ), ИМ в анамнезе и с ИБС без ИМ. Все пациенты были подвергнуты коронарографии с возможным ЧКВ. Все пациенты прошли этапы I и II сердечной реабилитации.

Опросник предлагался всем пациентам во время проведения ЧКВ и затем через 6 месяцев, как и тредмил-тест (TST) и эхокардиография (ЭХО). Результаты. Общий расход энергии, рассчитанный с помощью MLTPAQ, остался на прежнем уровне и был низкой интенсивности (<4 MET, <2000 kcal/

неделю) в 6 месяцев после ЧКВ. Отмечено увеличение физической работоспособности через 6 месяцев после первоначального ЧКВ: увеличение энергетических затрат (MET); максимального потребления кислорода (VO2max); максимальный сердечный ритм (HR ) был получен в ходе TST, снизилась частота пульса в спокойном состоянии (HRrest). ЭХО исследование показало улучшение ФВ ЛЖ,%.

Клиническое воздействие реабилитации: полезность исследования может быть использована в работе врачей-кардиологов или физиотерапевтов. Исследование позволит определить реальный уровень физической активности и физической выносливости пациентов, которые лечились с помощью ангиопластики. Кроме того, это самый простой и дешевый метод оценки. Заключение. Несмотря на увеличение физической способности и улучшение сердечной гемодинамики в результате ЧКВ, пациенты показали одинаковый уровень физической активности через 6 месяцев после ЧКВ.

Российский кардиологический журнал 2014, 4 (108), Англ.: 54-59

Ключевые слова: ишемическая болезнь сердца, чрескожное коронарное вмешательство, анкеты физической активности, тредмил-тест, эхокардиография.

Introduction

In recent years there have been many papers published on the research methods aimed at measurement of physical activity. Some were based on monitoring of selected physiological parameters such as heart rate and whole body movements with the use of accelerometers or pedometers [1—3]. Other were aimed at assessment of energy expenditure derived from food, using direct and indirect calorimetry, kinematic analysis as well as doubly labelled water [4]. In epidemiological studies, the application of such methods is limited due to high costs, potential contraindications, advanced age of subjects, their health status and low reliability. It seems that a questionnaire constitutes a simple and inexpensive tool in assessment of physical activity [6—9]. In some questionnaires only occupational activity is of interest, in others, only leisure time exercise, but many seek information about activity both on and off the job.

The questionnaires assess the physical activity over a wide age range for various periods of time — the previous 24 hr, the previous week, month or even a year [7, 9].

The data obtained in this way allows for calculation of average energy expenditure of an individual, which informs us whether the form, frequency and intensity of physical activity reach the values required for prevention and treatment of many so-called civilization diseases.

Such measurement is of great importance, since the sedentary lifestyle is one of the risk factor responsible for occurrence of IHD and at the same time physical activity constitutes a major factor in treatment and secondary prevention of IHD [10, 11].

However, the number of studies done on the application of questionnaires for clinic purposes in patients with IHD is limited. We attempted to answer the following questions:

1. What is the average weekly amount of physical activity and energy expenditure calculated using the MLTPAQ in patients with coronary artery disease (CAD) before and after percutaneous coronary intervention (PCI)?

2. Do obtained questionnaire results correlate with the level of physical capacity [assessed with submaximal treadmill exercise test (ET)] and cardiac haemodynamical parameter — Ejection Fraction (evaluated with echocardiography), making it a usable tool in clinical studies?

3. Is there a correlation between the obtained questionnaire results and combined endpoint?

Material and methods

The study group consisted of 211 patients, aged between 32—74 years (mean age of 56±7), among which there were patients with acute MI, with history of past MI and with IHD without MI. Patients with post-MI complications such as cardiogenic shock, circulatory arrest, pericarditis, resting arrhythmias and heart conductivity disorders were excluded from the study. All patients were informed about the type and aim of the research and they gave written

informed consent before participating in the study. Subjects were told that they may withdraw from the study at any time. The study was approved by the Senate Ethics Committee of the Academy of Physical Education in Katowice, Poland.

All subjects underwent coronarography procedure with optional percutaneous coronary intervention (PCI). Out of 154 patients 32 (20,77%) did not receive stent implantation, 108 subjects (70.12%) received one stent, while 8 (5,19%) two stents implantation. All patients underwent phase I, inpatient cardiac rehabilitation which lasted from 5 to 7 days. After hospitalization all patients were referred to phase II, 24-day cardiac rehabilitation in health resort (sanatorium). All subjects filled the MLTPAQ twice: first, at the time of hospitalization due to PCI procedure, and then for the second time after the lapse of 6 months. The MLTPAQ results enabled the calculation of the level of recreational physical activity and household activities during leisure time. The results were expressed in a weekly value [kcal/week] after dividing the calculated 6-month energy expenditure by 26 weeks. The following ranges of activity intensity were used: low [< 4 MET], medium [4 — < 6 MET] and high [> 6 MET], where 1 MET equals the resting metabolic rate, which is approximately 3.5 ml oxygen kg body weight per min . The value of total averaged weekly energy expenditure was calculated separately for recreational activity (RA) and household activity (HA) (shopping, cleaning, gardening, house remodelling and repairing). Additional categorization of weekly energy expenditure into 4 ranges was also made: < 999, 1000-1999, 2000-2999, > 3000 [kcal/week]. The MET for a given activity value was calculated according the Compendium of Physical Activities Tracking Guide [12]. In order to increase reliability of the questionnaire calculations (avoiding possible misunderstanding of some questions, especially those concerning the time of activity) the authors of this study read the questions of the MLTPAQ and filled in the questionnaires for patients during individual appointments.

The level of work capacity was assessed with the use of submaximal treadmill stress test (according to Bruce's protocol) performed 1-3 months before the initial PCI procedure and 6 months after. The following variables of stress test were subjected to statistical analysis: test duration [min], metabolic cost [MET], resting and the highest recorded value of heart rate [beats/min], maximal oxygen consumption VO2max [ml] and the reason for stress test termination: submaximal value of HRmax (85%) calculated with formula: HR max = 208-07 x age, fatigue, stenocardia, changes of S-T segment in electrocardiogram (ECG), occurrence of arrhythmias, heart conductivity disorders and excessive increase in arterial blood pressure. The value of VO2max was calculated according to the following formula [13]:

VO2max = 13,3-0,03 (t) + 0,297 (t 2) — 0,0077 (t.2) + 4,2 (CHS),

where, t — time [minutes], CHS — cardiac health status, 1- patients with angina pectoris, after MI, after

Table 1

Results of treadmill stress test at the time of PCI and 6 months after

Parametr at the time of PCI, N = 154 6 months after PCI, N = 150 P

Stress test time [min] 4,24±2,22 6,32±3,12 <0,001

MET 6,52±1,26 8,21±2,86 <0,001

VO2max [ml] 28,23±5,94 32,52±8,25 <0,001

Resting HR [beats/min] 72±4,23 70±6,22 <0,001

HR at the test [beats/min] max L ' J 118±14,52 129±16,47 <0,001

Abbreviations: PCI — percutaneous coronary intervention, MET — metabolic cost, VO2max — maximal oxygen consumption, HR — resting heart rate, HR — maximal

heart rate.

Table 2

Indications for treadmill stress test termination

Indications for stress test at the time of PCI 6 months after PCI

termination N % N %

Reaching submaximal HR 19 12,33 118 78,66

Otherf 135 87,67 32 21,34

Total 154 100 150 100

P <0,001

Abbreviations: PCI — percutaneous coronary intervention, HR — heart rate. f stenocardia, S-T segment changes in ECG, occurrence of arrhythmias and heart conductivity disorders, excessive increase in arterial blood pressure.

Table 3

Echocardiography results

Parametr at the time of PCI, N = 154 6 months after PCI, N = 150 P

LVEF% 50,45±7,21 51,36±6,12 <0,02

Abbreviations: PCI — percutaneous coronary intervention, LVEF% — left ventricular ejection fraction.

PCI, 0 — patients without clinical symptoms of angina pectoris, without history of MI or PCI.

Left ventricular ejection fraction (LVEF%) was analyzed. The assessment of heart structure was done with 2-dimennsional echocardiography (HP Sonos 1100) by a physician, cardiology specialist, after completion of echocardiography training.

All statistical analyses were performed using Statistica (v. 7.1) software, Statsoft USA and MedCalc software (v.8.0.0.1) by F. Schoonjans and included the calculation of means and standard deviations (SD) of variables. The distribution of means was evaluated with Wilk-Shapiro test for normality. A criterion of p<.05 defined statistical significance. Student's t-test for independent variables with normal distribution was used. This test was preceded by the Fisher's test for verification of the homogeneity of variance. In case the variance was not equal, Sattherwaite's test was used. Student's t-test for dependent variables was also used, as well as one-way variance analysis proceeded by Bartlett's test for verification of variance homogeneity.

For variables with non-normal distribution, U MannWhitney test, Kruskall-Wallis ANOVA test and Sperman's rang correlation test were used.

Results

Out of 211 patients who initially underwent PCI procedure, there were 207 subjected to the second questionnaire administration (2 patients died due to coronary insufficiency in second and fifth month after the PCI, 2 patients resigned from the study due to general discomfort). Compared to the stress test performed at the time of the initial PCI procedure, the improvement of patients' physical capacity was noted during the treadmill stress test: increased metabolic cost (MET); maximal oxygen consumption (VO2max); maximal heart rate (HRmax) obtained during the test and decreased resting heart rate (HR ) (Table 1). The number of patients who terminated the stress test due to pathological reasons reduced (Table 2).

After the 6-month period, there was a favourable tendency noted in the changes of heart hemodynamic, though only in the case of EF% statistical significance was observed (Table 3).

The total energy expenditure from the leisure time activities calculated with the MLTPAQ was higher 6 months after the angioplasty procedure (2829,52 vs 2799,92kcal/week). As far as physical activity of low intensity was concerned, there was an increase noted (1759,30 vs 1811,06 kcal/week). The values of activity of medium and high intensity dropped from 1300,99 to 1190,46 and from 714,63 to 491,73 kcal/week, respectively. Nevertheless, none of the above changes were statistically significant. The value of recreational activity was higher 6 months after the angioplasty for the range of low intensity (<4 MET) and in majority of patients did not exceed 3000 kcal/week. For the range of medium intensity (4-6 MET) it stayed under 2000 kcal/week in majority of patients. In the range of high intensity (>6MET) it did not exceed 1000 kcal/week in those few patients who presented with that level of intensity. In case of household activity, there was an increase noted in medium range of intensity (4-6MET) which did not exceed 3000 kcal/week in majority of patients. For the household activities of high intensity

Table 4

Types and ranges of physical activity energy expenditure calculated with the MLTPAQ

Parameter below 999 kcal 1000-1999 kcal 2000-2999 kcal over 3000 kcal TOTAL

before 6 months before PCI 6 months before 6 months after before 6 months before 6 months P

PCI after PCI after PCI PCI PCI PCI after PCI PCI after PCI.

Low intensity < 4 MET

RA Mean 498,18 521,75 1333,52 1451,66 2445,65 2512,62 4186,59 4105,97 1619,94 1707,99 <0,24

SD 270,17 212,64 216,62 220,38 329,21 312,40 875,31 601,03 1232,93 1104,06

N 51 52 54 65 20 20 7 6 132 143

HA Mean 191,46 429,11 1210,46 — 2312,30 2403,93 4116,90 4000,07 1632,29 1320,53 <0,34

SD 45,54 201,79 33,97 — — 152,60 427,10 187,11 1611,22 1481,89

N 5 10 3 0 1 2 4 4 13 16

Total Mean 435,65 501,51 1235,39 1366,11 2568,12 2489,92 4452,98 4481,01 1729,10 1801,14 <0,31

SD 292,09 232,50 233,37 222,51 307,08 309,43 1076,02 900,03 1421,13 1291,56

N 56 51 23 35 40 7 19 3 131 138

Medium intensity 4 — >6 MET

RA Mean 309,90 420,33 1318,01 1501,26 2500,76 2401,10 3048,04 4623,12 545,12 601,18 <0,11

SD 253,55 261,49 324,92 223,30 190,19 288,27 — — 534,81 641,21

N 84 85 22 10 9 4 4 2 119 101

HA Mean 371,91 524,22 1418,24 1495,28 2417,56 2484,60 4410,14 3765,73 1064,42 1011,12 <0,45

SD 245,38 290,29 278,60 302,84 99,96 412,87 1295,59 531,09 1529,76 1129,48

N 65 66 21 28 5 5 13 11 104 110

Total Mean 415,37 515,90 1541,89 1352,59 2320,16 2355,92 4221,67 4112,71 1289,85 1088,42 <0,71

SD 111,00 207,23 292,12 296,89 125,83 283,95 1007,42 568,86 1326,26 1198,55

N 74 81 34 29 12 15 12 8 132 133

High intensity >6 MET

RA Mean 372,70 321,41 1226,15 1561,54 — 2225,00 3113,01 5226,14 511,94 643,90 <0,6

SD 224,21 232,07 22,12 — — — — — 621,73 1005,01

N 24 21 3 1 0 1 1 1 28 24

HA Mean 332,15 231,94 1409,01 1206,15 2015,38 — 4644,61 — 723,74 195,34 <0,6

SD 180,21 181,79 — — — — — — 1220,53 252,87

N 18 25 2 2 1 0 5 0 26 28

Total Mean 361,61 281,26 1354,15 1396,15 2195,38 2068,45 4126,15 5106,14 700,63 391,73 <0,9

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SD 272,61 219,48 307,81 230,48 — — 1293,36 — 1092,74 806,73

N 34 39 6 3 2 1 3 1 45 44

Total energy Mean 581,11 589,29 1449,74 1530,92 2477,41 2499,81 4796,96 4536,78 2363,11 2412,53 <0,6

expenditure SD 292,31 199,13 154,43 110,69 100,83 154,70 1327,55 1107,28 1647,09 1599,55

N 28 23 45 42 37 48 44 37 154 150

Abbreviations:

Total — energy

: PCI — percutaneous expenditure of either RA,

coronary intervention, RA — energy expenditure of recreational activity, HA or both forms of activity, SD — standard deviation.

HA — energy expenditure of household activity,

(>6 MET) there was a significant drop of the energy expenditure noted in all ranges (Table 4).

There was a significant increase of work tolerance noted during the stress test 6 months after the angioplasty. There were considerable changes in values of all observed parameters. Patients, whose physical activity in leisure time was in the range of2000—2999 and over 3000 kcal/week, obtained the most significant improvement during the stress test (Table 5).

The echocardiography examination performed 6 months after the angioplasty showed improvement of the heart structure dimensions. Statistically significant changes (within the normal range) considered the LVESD and LVEF% values. In the group of patients whose weekly

energy expenditure was below 2000 kcal/week, there was a slight increase of the dimensions in majority of parameters, except for LVEF%, where there was a small decrease (within the normal range) observed in the group of patients with weekly energy expenditure under 999 kcal/week (Table 6).

There were weak correlations observed between total energy expenditure calculated with the MLTPAQ stress test parameters and ECHO results (Table 7 and Table 8).

Discussion

The average amount of weekly energy expenditure related to recreational activity, and therefore the one which is ofgreat importance for prevention of cardiovascular

Table 5

Selected parameters of stress test in relation to the intensity ranges of activity calculated with the MLTPAQ

Parameter below 999 kcal 1000-1999 kcal 2000-2999 kcal over 3000 kcal TOTAL

before 6 months before 6 months before 6 months before 6 months before 6 months P

PCI after PCI PCI after PCI PCI after PCI PCI after PCI PCI after PCI

Test duration Mean 5,70 5,64 5,71 7,16 5,31 7,35 6,15 8,18 4,24 6,32 <0,001

[min] SD 2,79 2,40 2,44 2,06 2,57 2,70 2,86 2,39 2,22 3,12