Methods

Population

Between January 2006 and April 2008, 825 cardiovascular screenings were performed at the University Centre of Sports Medicine in Groningen. The data of these screenings were collected, 397 of which were excluded because participants were under 12 or over 35 years of age, because a participant had undergone multiple screenings (Lausanne) of which only the first one was included, or because participants were known to have cardiovascular disease before the screening. A total of 428 screenings remained and were included in this study (fig 1).

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Figure 1

Overview of population included.

Lausanne screening

From 1 January 2006 the Lausanne recommendations were implemented in the cardiovascular screening of athletes aged 12–35 years at the University Centre of Sports Medicine in Groningen, The Netherlands.

The cardiovascular screening was divided into three stages. The first stage consisted of the cardiovascular screening according to the Lausanne recommendations. The athletes with no abnormalities at this screening (negative screening outcome) were found eligible for sports participation. When the screening showed abnormalities, participants underwent primary additional testing (stage 2). Based on the suspected type of cardiovascular disease, these (stage 2) tests consisted of echocardiography, an exercise stress test, a signal averaged ECG and/or a 24-h ECG monitoring. When these tests showed no abnormalities and there was no suspicion of a cardiovascular disease, the athletes were found eligible for sports participation (false-positive screening outcome). When the tests showed abnormalities consistent with a type of cardiovascular disease, or when a type of cardiovascular disease was suspected, the athletes underwent secondary additional testing (stage 3). When after these tests a cardiovascular disease could be excluded, the athletes were found eligible for sports participation (false-positive screening outcome). When the additional test showed evidence of a cardiovascular disease the athletes were (temporarily) disqualified from sports participation (positive screening outcome) (fig 2).

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Figure 2

The three stages of the Lausanne screening. Absolute numbers and percentages are both shown. *Two athletes were diagnosed as having a cardiovascular disease at stage 1 (one hypertension, one Wolff–Parkinson–White syndrome) and required no stage 2 additional testing. Therefore, only 55 athletes remained for stage 2 additional testing. ECG, electrocardiogram; PE, physical examination.

Data collection

Data were collected for all three stages.

The data collected for stage 1 consisted of a questionnaire containing the reason for screening, information about sports participation and the Lausanne questionnaire (personal history, family history and cardiovascular symptoms). In addition, data were collected on the physical examination (according to the Lausanne recommendations) and the ECG.

When participants were referred for primary and secondary additional cardiovascular testing these data were also collected (stages 2 and 3). The reason for referral for additional testing was also documented. Finally, the outcome of the screening was noted.

Statistical analysis

Statistical analysis was done using SPSS version 14.0.

Results

Population

Between January 2006 and April 2008, screenings of 428 athletes were included. Of these 428 athletes 322 (75%) were male, and the average age at the time of screening was 22 years of age (range 12–35 years). Seventy-seven per cent of these athletes underwent a mandatory screening because of their high level of sports participation and 7% underwent the screening because of cardiovascular symptoms. The athletes participated mostly in rowing (34%), soccer (21%) and cycling (19%) (table 1).

Lausanne screening (stage 1)

Of all athletes, 371 (87%) had no abnormalities in their family or personal history as was shown by a questionnaire, nor did they have abnormalities at physical examination or in their ECG. They were therefore found eligible for sports participation. A total of 57 (13%) athletes showed abnormalities at the screening and therefore they had to undergo primary additional testing (stage 2). These abnormalities consisted of the following (see also table 2).

Family and personal history

Twenty-three athletes, who were referred, had abnormalities in their personal and family history; 13 of these 23 athletes were referred only because of abnormalities in their family and personal history. The other 10 athletes had abnormalities at physical examination and/or on their ECG. Most abnormalities consisted of a positive family history of sudden cardiac death (<50 years of age) and/or cardiovascular disease (13) or symptoms of palpitations (11) (table 2).

Physical examination

The physical examination was abnormal in 11 of the 57 athletes. Three times a brachial blood pressure greater than 140/90 mm Hg on more than one reading was found and in eight cases the abnormality consisted of a heart murmur (table 2).

Electrocardiogram

At the screening 36 athletes (8%) were found to have an abnormal ECG according to the Lausanne criteria. The most common ECG abnormalities included increased voltage (24%) and ST-segment depression or T-wave flattening or inversion in two or more leads (22%). A total of 13 ECG showed an increased voltage. In six of these 13 cases the increased voltage was the only abnormality found at the screening (including family and personal history and physical examination). All ECG abnormalities that were found are listed in table 3. In 27 cases (6.3%) athletes were referred for additional testing based only on abnormalities of their ECG (table 2).

Additional tests (stage 2)

A total of 57 (13%) athletes had abnormalities at the screening, which was the reason for primary additional testing (stage 2).

Of these 57 athletes, one athlete had a brachial blood pressure greater than 140/90 mm Hg on more than one reading and was referred to his physician for treatment. No additional testing was performed. Another athlete was diagnosed as having Wolff–Parkinson–White syndrome, based on the ECG (delta wave and PR <120 ms). The athlete was referred to a cardiologist for further treatment through electrophysiological testing and possible radiofrequency catheter ablation and was not referred for additional stage 2 testing.

The remaining 55 athletes had in total 90 additional tests (34, 11 and 10 athletes had one, two or more additional tests, respectively). Mostly these tests were echocardiography (49; 54%). Exercise stress test and 24 h ECG registration monitoring was completed in 23 and 14 athletes, respectively (table 4).

The six athletes, whose only abnormality was an increased voltage on their ECG, were all referred for echocardiography. In all six cases no abnormalities were found at echocardiography.

The results of the additional tests necessitated further evaluation and/or treatment in 11 athletes. Together with the two athletes with already established cardiovascular disease, 13 of the 57 (23%) athletes were suspected of having cardiovascular disease after stage 2 testing. The individual characteristics of these 13 athletes are shown in table 5.

Seven of these 13 athletes underwent stage 3 testing in order to confirm or dismiss their suspected cardiovascular disease.

A total of 44 athletes of the 55 athletes who underwent stage 2 testing showed no abnormalities in these tests and were found eligible for sports participation (false-positive screening outcome).

Additional tests (stage 3)

Additional stage 3 testing was indicated in only seven athletes (1.6%). A total of four magnetic resonance imaging scans were performed, one in combination with an electron beam tomography scan. The athlete who was diagnosed as having WPW syndrome underwent electrophysiological testing with the possibility of radiofrequency catheter ablation. In two cases athletes were also referred to the Department of Cardiogenetics for genetic testing. Furthermore, one lung perfusion scan and one chest x ray were performed.

In four of these seven cases a cardiovascular diagnosis was made. In three athletes the suspicion of cardiovascular disease was cleared and they were found eligible for sports participation (false-positive screening outcome) (table 5).

Cardiovascular diagnoses and sport eligibility

Of the 428 athletes screened between January 2006 and April 2008, 10 (2%) were diagnosed as having a cardiovascular disease. Three athletes (0.7%) received a (temporary) sports restriction (table 5).

Three athletes received a diagnosis of hypertension and were referred to their physician for treatment. They received no sports restriction.

Two athletes had diagnoses of atrioventricular nodal re-entry tachycardia (circus movement tachycardia). Even though the additional test did not show any abnormalities, their history was so specific that there was still a high suspicion of a benign supraventricular tachycardia. Because of the benign nature of the tachycardia and the minor disability the athletes perceived no treatment was indicated. The athletes received no sports restriction.

One athlete was diagnosed as having WPW syndrome. Electrophysiological testing showed a benign accessory inferolateral tract on the right. Because of the benign nature and the athlete’s wishes, no radiofrequency catheter ablation was performed. The athlete received no sports restriction.

One athlete was diagnosed as having a minor insufficient pulmonary valve on the echocardiography. The athlete received no sports restriction but was advised to repeat echocardiography after one year.

Two athletes were diagnosed as having congenital long-QT syndrome. They received treatment with β-blocking agents and they received a temporary sports restriction. They were also advised not to use any QT-prolonging medication.

One athlete was diagnosed has having arrhythmogenic right ventricular cardiomyopathy (ARVC). The athlete received a complete sports restriction for all competitive sports. The work-up of this athlete was still in progress at the time the data were collected (table 5).

The number of athletes needed to screen to find a single athlete with a cardiovascular disease for which a (temporary) sports restriction is warranted was 143.

Discussion

The Lausanne recommendations proposed in 2005 by Corrado et al1 are based largely on 30 years experience in the Italian Veneto region. Since then there has been much debate as to whether these recommendations should be incorporated, and if so, in what form.13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 This study, although small in sample size, gives a first insight into the experience with the Lausanne recommendations in Groningen, The Netherlands.

Of the 428 athletes who were screened between January 2006 and April 2008, a total of 13% (55) was referred for additional testing because of abnormalities at the screening. This percentage is comparable to the percentage found by Corrado and colleagues,1 2 3 who referred 9% of the competitive athletes for additional testing.

In this study we found a false-positive screening outcome of 11%. Again this percentage corresponds to the percentage found by Corrado and colleagues,1 2 3 who had a false-positive screening outcome of (7%). Our slightly higher false-positive rate may be partly related to the population screened, with 7% of our athletes being referred for screening because of cardiovascular symptoms.

When looking at the cardiovascular diseases (2%) and (temporary) sports restriction (0.7%), the percentages also seem to match well with Corrado and colleagues.1 2 3 They found that 2% of the athletes who were screened had a cardiovascular disease, which was the reason for sports restriction in all cases.

When focusing on the medical consumption used for additional testing, the results of our study are comparable to the medical consumption needed by Corrado and colleagues.1 2 3 We documented a consumption of 62%, 20% and 18% for one, two and three or more additional tests in stage 2, respectively. Corrado and colleagues1 2 3 found a similar consumption (66%, 21% and 12%, respectively).We documented a stage 3 consumption of 1.6%, which was comparable to that of Corrado and colleagues,1 2 3 who found a consumption of 2%.

This study shows that when looking at the Lausanne recommendations, the Dutch population seems comparable to the Italian results in abnormal screening outcome, (false)-positive screening outcome and medical consumption. Even though this study is based on a small sample, the similarities with Corrado and colleagues1 2 3 are striking. Also the cardiovascular diseases that were found show more similarities with the Italian population than, for example, the population of the USA. We found one athlete with ARVC and two with a Long QT syndrome, whereas we found no hypertrophic cardiomyopathy (HCM). This is more in line with Corrado and colleagues,1 2 3 who found that most sudden cardiac deaths were related to ARVC and diseases of the conduction system, than with Maron et al,9 who found that most sudden cardiac deaths in the USA were caused by HCM.

Part of the debate on the Lausanne recommendations has been the inclusion of an ECG and the proposed ECG criteria.4 5 6 7 8 9 10 11 12 25 26 27 28 29 30 31 32 33 34 35 36 37

Concern for false-positive results and costly additional work-ups by the inclusion of ECG is cited as a major obstacle to the wide adoption of this protocol.4 5 7 9 11 12 In this study 6.3% of the athletes were referred for additional testing only because of an abnormal ECG. To us this seems an acceptable percentage.

When looking at the ECG criteria, the focus of the debate has been partly on the criteria of increased voltage (amplitude of R or S-wave in a standard lead ⩾2 mV, S-wave in lead V1 or V2 ⩾3 mV, or R-wave in lead V5 or V6 ⩾3 mV). Questions have been raised as to whether voltage criteria alone (in the absence of T-wave inversion, ST-depression, or pathological Q-waves) represent a significant finding suggestive of HCM or are just a part of athletic heart adaptations. Recent studies suggest that voltage criteria (for left ventricular hypertrophy) alone do not represent a pathological finding.37 In this study six athletes were referred for additional testing based only on an increased voltage on their ECG. In all six cases additional echocardiography showed no signs of HCM. If we were to exclude these athletes, the number of athletes with a positive (stage 1) screening outcome would be 11.9% (51) and the number of athletes referred for additional (stage 2) testing based only on an abnormal ECG would be 4.9% (21). Also the total false-positive screening outcome would decrease from 10.9% (47) to 9.6% (41).

When we look at the number of athletes needed to be screened to find a single athlete with a cardiovascular disease that warrants a (temporary) sports restriction, a total of 143 athletes seems acceptable. Although this does not provide evidence for the effectiveness of the Lausanne recommendations, it does show that the Lausanne recommendation are an effective screening tool to detect potentially lethal cardiovascular diseases.

The numbers found in this study are possibly a slight overestimate of the percentages one would see if conducting only mandatory screening in athletes according to the Lausanne recommendations. In this study 77% of the athletes were screened because it was mandatory, but 7% were screened because of cardiovascular symptoms. Also, the fact that we only included the first cardiovascular screening might result in a small overestimate of the percentage of stage 1 abnormal screening outcome.

The sports participation of our study population is not a good reflection of sports activities in The Netherlands, with soccer as the leading sport by far, whereas rowing is only a minor sport, but in our population was the most performed sport. This may have led to a referral bias. This difference may be explained by the fact that in rowing and cycling a cardiovascular screening is mandatory for all competing athletes, whereas in soccer this is only the case for professional players.

This study shows the data of a small sample of competitive athletes in The Netherlands. One could therefore argue that conclusions should be drawn with caution. On the other hand, the outcome of this study shows remarkable similarities with the findings of Corrado and colleagues.1 2 3 Therefore, although the sample size is small, we feel this study is representative of the Dutch situation.

Conclusion

This study shows that when we implement the Lausanne recommendations in The Netherlands, the screening results resemble those found by Corrado and colleagues1 2 3 in Italy. The screening results in this study were defined as the percentage of false-positive screening results, the cardiovascular diseases detected and the medical consumption.

This study demonstrates that the false-positive screening outcome and additional testing required based on ECG abnormalities are acceptable.

Finally, this study shows that the number of athletes needed to screen to detect a single athlete with a potentially lethal cardiovascular disease is 143.