Skip Navigation

European Journal of Heart Failure 2008 10(11):1123-1126; doi:10.1016/j.ejheart.2008.09.005
This Article
Right arrow Abstract Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Malek, L. A.
Right arrow Articles by Ruzyllo, W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Malek, L. A.
Right arrow Articles by Ruzyllo, W.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© 2008 European Society of Cardiology

Long term exercise capacity in patients with hypertrophic cardiomyopathy treated with percutaneous transluminal septal myocardial ablation

Lukasz A. Maleka,*, Lidia Chojnowskaa, Mariusz Klopotowskia, Renata Maczynskaa, Marcin Demkowa, Adam Witkowskia, Beata Kusmierczykb, Ewa Piotrowiczc, Marek Konkab, Maciej Dabrowskia and Witold Ruzylloa

a 1st Department of Coronary Artery Disease and Catheterization Laboratory, Institute of Cardiology Warsaw, Poland
b Echocardiographic Laboratory, Institute of Cardiology Warsaw, Poland
c Department of Cardiac Rehabilitation and Noninvasive Electrocardiology, Institute of Cardiology Warsaw, Poland

* Corresponding author. 1st Coronary Disease Department and Catheterization Laboratory, Institute of Cardiology, Alpejska 42, 04-628 Warsaw, Poland. Tel.: +48 22 3434267; fax: +48 22 6133819. E-mail address: lmalek{at}ikard.pl (L.A. Malek)


   Abstract
Top
 Abstract
1. Background
 2. Aim
 3. Materials and methods
 4. Results
 5. Conclusions
 References
 
Background: In hypertrophic obstructive cardiomyopathy, percutaneous transluminal septal myocardial ablation (PTSMA) improves functional capacity in the short term. However, long term functional capacity is unknown.

Aim: To assess the long term exercise capacity of patients with hypertrophic obstructive cardiomyopathy undergoing PTSMA.

Methods: Twenty three patients (56.5% male, mean age 44.5±13.6 years) who underwent PTSMA were included. All patients had also undergone a symptom limited cardiopulmonary exercise treadmill test before the procedure, then after 3 months (early follow-up) and after a mean 7.2±1.0 years (long term follow-up).

Results: Before PTSMA, mean maximal pressure gradient in the left outflow tract (LVOTGmax) was 82±29 mmHg, 17 patients had NYHA functional class ≥ III and peak oxygen uptake (pVO2) was 18±4 ml/kg/min. PTSMA led to a reduction in mean LVOTGmax (to 29 ± 19 mmHg. p<.0001), improvement of heart failure symptoms (NYHA≥III in 1 patient, p<.0001) and an increase of pVO2 (to 22±6 ml/kg/min, p =.0002) at short term. LVOTGmax, functional class and pVO2 did not change significantly during long term follow-up compared to early follow-up. However, there was a continuous improvement in percentage predicted pVO2 over time.

Conclusions: In patients with hypertrophic obstructive cardiomyopathy and symptoms of heart failure, PTSMA leads to stable long term improvement of objectively measured exercise capacity.

Key Words: Hypertrophic cardiomyopathy • Left ventricular outflow tract obstruction • Percutaneous transluminal septal myocardial ablation • Exercise capacity • Follow-up

Received May 9, 2008; Revised August 4, 2008; Accepted September 17, 2008


   1. Background
Top
 Abstract
 1. Background
2. Aim
 3. Materials and methods
 4. Results
 5. Conclusions
 References
 
Hypertrophic cardiomyopathy is a genetic disorder, which manifests as ventricular hypertrophy accompanied by obstruction of the left ventricular outflow tract (LVOT) in about one third of patients [1]. If the pressure gradient in the LVOT persists despite medical treatment and leads to severe limiting clinical symptoms, patients should be considered for non-medical therapies [1]. One of the established methods of pressure gradient reduction is percutaneous transluminal septal myocardial ablation (PTSMA) [2]. Previous studies to evaluate outcome in patients who have undergone PTSMA, mostly using echocardiography and functional assessment by NYHA class with follow-up ranging from 3 months to 5 years, have shown that the method is safe and effective [2-13]. However, little is known about objectively measured exercise capacity more than 5 years after the procedure.


   2. Aim
Top
 Abstract
 1. Background
 2. Aim
3. Materials and methods
 4. Results
 5. Conclusions
 References
 
To assess the long term effects of PTSMA using cardiopulmonary exercise testing on a treadmill, as well as clinical and echocardiographic parameters.


   3. Materials and methods
Top
 Abstract
 1. Background
 2. Aim
 3. Materials and methods
4. Results
 5. Conclusions
 References
 
The study included 27 patients who had PTSMA performed between 1st November 1997 and 31st December 2002. All patients had undergone cardiopulmonary exercise testing on treadmill both before the PTSMA procedure and 3 months after the procedure (short term follow-up). The short and mid term outcomes in this group have been presented previously [6,9]. To test long term exercise capacity, all patients were asked to undergo another cardiopulmonary exercise test on a treadmill at least 5 years after the procedure. The mean duration of long term follow-up was 7.2±1.0 years. Four of the 27 patients were excluded from the study because they could not perform the test due to extracardiac limitations (Parkinson disease, status post-hip replacement, sclerosis multiplex).Therefore data on long term follow-up in 23 patients are reported.

Additionally all patients had a clinical assessment and transthoracic echocardiography test performed early before PTSMA, 3 months after the procedure and at the end of the follow-up.

Details of the PTSMA procedure and the methodology for the echocardiographic evaluation and the cardiopulmonary treadmill test have been described in detail previously [6,9]. We used the same study protocols each time to monitor changes over time. All patients were exercised to maximum with respiratory quotient (RQ)>1.0. Cardioactive medications were discontinued at each cardiopulmonary test.

3.1. Statistical methods
All results for continuous variables with normal distribution are expressed as mean±standard deviation (SD) and skewed variables as median and interquartile range (IQR). Differences between categorical variables were analyzed with the Fisher exact or {chi}2 tests where appropriate. Student-t test for paired samples or Wilcoxon rank sum test for paired samples, were used to compare continuous variables, as appropriate. All tests were two-sided with a significance level of p<.05. All statistical analyses were performed with SAS software version 9e (SAS Institute Inc., Cary, NY).


   4. Results
Top
 Abstract
 1. Background
 2. Aim
 3. Materials and methods
 4. Results
5. Conclusions
 References
 
4.1. Echocardiographic and clinical assessment
Studied patients had a mean age of 44.5±13 years and 13 were male (56.5%). A pacemaker was implanted in 3 patients (13%) after the PTSMA procedure. Before PTSMA, all patients had a mean maximal left ventricular outflow tract gradient (LVOTGmax) ≥50 mmHg and 17 (74%) had NYHA≥III heart failure (Table 1). PTSMA led to a significant reduction of mean LVOTGmax and a decrease in the frequency of systolic anterior movement and moderate or severe mitral regurgitation at short term. At 3 months from the procedure, mean LVOTGmax was reduced to <50 mmHg in 20 patients (87%) and <30 mmHg in 14 patients (61%). These changes caused a marked improvement in symptoms of heart failure and angina.


View this table:
[in this window]
[in a new window]

  		Table 1 Baseline characteristics of the studied population (n=23)

 
The mean LVOTGmax, frequency of systolic anterior movement (SAM) and mitral regurgitation remained stable at long term follow-up. Individual changes in mean LVOTGmax at different time points are presented in Fig. 1A. Despite significant changes in the left ventricular and atrial sizes and marked reduction of the left ventricular ejection fraction (LVEF) at long term in comparison to 3 months post-PTSMA, there was no significant deterioration of symptoms of heart failure or angina.


Figure 01
View larger version (30K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Fig. 1 Individual differences in A) mean maximal left ventricular outflow tract gradient (LVOTGmax) and B) peak oxygen uptake (pVO2) over time.

 
4.2. Exercise capacity assessment
Assessment of exercise capacity showed that PTSMA leads to a significant increase in mean exercise time, peak oxygen uptake (pVO2) and percentage predicted peak oxygen uptake (%pVO2) for sex and age at short term post-ablation (Table 2). Although there was a tendency for reduction of mean exercise time during long term follow-up, the mean pVO2 remained unchanged and there was a continuous increase in %pVO2. Individual changes in pVO2 at different time points are presented in Fig. 1B.


View this table:
[in this window]
[in a new window]

  		Table 2 Results of the cardiopulmonary exercise testing (n=23)

 

   5. Conclusions
Top
 Abstract
 1. Background
 2. Aim
 3. Materials and methods
 4. Results
 5. Conclusions
References
 
The main and novel finding of our study is that short term improvement of exercise capacity after PTSMA is sustained long term.

It was previously demonstrated that left ventricular outflow tract gradients are inversely related to peak V02 uptake and therefore abolition of mechanical obstruction should result in an improvement in exercise capacity [13]. Indeed short and mid term studies prove that there is an increase in exercise capacity after successful PTSMA measured with peak V02 uptake [8,12]. We show that this effect is stable and may even be increased as demonstrated by changes in percentage predicted peak oxygen uptake. To our knowledge this is the first study of functional assessment in PTSMA patients, over 5 years after the procedure, using cardiopulmonary testing on a treadmill. A few studies have analyzed very long term follow-up (5 or more years) of patients post-PTSMA, using methods other then cardiopulmonary testing and have demonstrated haemodynamic, clinical and exercise improvement [14,15].

One of the reasons for the improvement in exercise capacity, which we are however not able to prove, might be better conditioning and fitness achieved after successful limitation of left ventricular obstruction.

Objective improvement in exercise capacity occurred despite an increase in left ventricular cavity size (LVEDD, LVESD), left atrial size and a decrease in left ventricular ejection fraction. However, changes in both left ventricular diameters were within the normal range and ejection fraction decreased from hyperkinetic to a normal value. The only variable to be considered negative was LA diameter, which changed towards more abnormal values. Several studies with sufficiently long observation periods have shown that these changes in LV parameters are typical for ageing patients with hypertrophic cardiomyopathy irrespective of LVOTG and PTSMA [16-18]. A parallel increase in LVEDD and LVESD at long term suggests that there was not much change in resting stroke volume. It is likely, but speculative, that during physical effort the systolic function and stroke volume had gained reserve to increase. This progressive improvement in LV mechanics might have translated into better exercise capacity.

A limitation of our study is the relatively small group of studied patients. However, the accurate method of exercise capacity assessment enabled the detection of significant changes [19,20].


   References
Top
 Abstract
 1. Background
 2. Aim
 3. Materials and methods
 4. Results
 5. Conclusions
 References
 

  1. American College of Cardiology/European Society of Cardiology Clinical Expert Consensus Document on Hypertrophic Cardiomyopathy. A report of the American College of Cardiology Foundation Task Force on Clinical Expert Consensus Documents and the European Society of Cardiology Committee for Practice Guidelines. Eur Heart J (2003) 24:1965–1991.[Free Full Text]
  2. Sigwart U. Non-surgical myocardial reduction for hypertrophic obstructive cardiomyopathy. Lancet (1995) 346:211–214.[CrossRef][Web of Science][Medline]
  3. Knight C., Kurbaan A.S., Seggewiss H., et al. Nonsurgical septal reduction for hypertrophic cardiomyopathy. Circulation (1997) 95:2075–2081.[Abstract/Free Full Text]
  4. Geitzen F.H., Leuner C.h.J., Raute-Kreinsen U., et al. Acute and long-term results after transcoronary ablation of septal hypertrophy (TASH). Eur Heart J (1999) 20:1342–1354.[Abstract/Free Full Text]
  5. Faber L., Meissner A., Ziemssen P., et al. Percutaneous transluminal septal myocardial ablation for hypertrophic obstructive cardiomyopathy: long term follow-up of the first series of 25 patients. Heart (2000) 83:326–331.[Abstract/Free Full Text]
  6. Ruzyllo W., Chojnowska L., Demkow M., et al. Left ventricular outflow tract gradient decrease with non-surgical myocardial reduction improves exercise capacity in patients with hypertrophic obstructive cardiomyopathy. Eur Heart J (2000) 21:770–777.[Abstract/Free Full Text]
  7. Mazur W., Nagueh S.F., Lakkis N.M., et al. Regression of left ventricular hypertrophy after nonsurgical septal reduction therapy for hypertrophic obstructive cardiomyopathy. Circulation (2001) 103:1492–1496.[Abstract/Free Full Text]
  8. Firoozi S., Elliott P.M., Sharma S., et al. Septal myotomy-myectomy and transcoronary septal alcohol ablation in hypertrophic obstructive cardiomyopathy. Eur Heart J (2002) 23:1617–1624.[Abstract/Free Full Text]
  9. Chojnowska L., Ruzyllo W., Witkowski A., et al. Early and long-term results of non-surgical septal reduction in patients with hypertrophic cardiomyopathy. Kardiol Pol (2003) 10:269–282.
  10. Maron M.S., Olivotto I., Betocchi S., et al. Effect of left ventricular outflow tract obstruction on clinical outcome in hypertrophic cardiomyopathy. N Engl J Med (2003) 348:295–303.[Abstract/Free Full Text]
  11. Guo H., Wang J., Chen J., et al. Percutaneous transluminal septal myocardial ablation in hypertrophic obstructive cardiomyopathy: acute results and three-year noninvasive follow-up in 18 patients. Can J Cardiol (2004) 20:779–782.[Web of Science][Medline]
  12. Faber L., Seggewiss H., Welge D., et al. Echo-guided percutaneous septal ablation for symptomatic hypertrophic obstructive cardiomyopathy: 7 years of experience. Eur J Echocardiography (2004) 5:347–355.[CrossRef]
  13. Kim J.J., Lee C.W., Park S.W., et al. Improvement in exercise capacity and exercise blood pressure response after transcoronary alcohol ablation therapy of septal hypertrophy in hypertrophic cardiomyopathy. Am J Cardiol (1999) 83:1220–1223.[CrossRef][Web of Science][Medline]
  14. Seggewiss H., Rigopoulos A., Welge D., et al. Long-term follow-up after percutaneous septal ablation in hypertrophic obstructive cardiomyopathy. Clin Res Cardiol (2007) 96:856–863.[CrossRef][Web of Science][Medline]
  15. Fernandes V.L., Nagueh S.F., Wang W., et al. A prospective follow-up of alcohol septal ablation for symptomatic hypertrophic obstructive cardiomyopathy—the Baylor experience (1996-2002). Clin Cardiol (2005) 28:124–130.[Web of Science][Medline]
  16. Spirito P., Maron B.J., Bonow R.O., et al. Occurrence and significance of progressive left ventricular wall thinning and relative cavity dilation in hypertrophic cardiomyopathy. Am J Cardiol (1987) 60:123–129.[CrossRef][Web of Science][Medline]
  17. Thaman R., Gimeno J.R., Reith S., et al. Progressive left ventricular remodeling in patients with hypertrophic cardiomyopathy and severe left ventricular hypertrophy. J Am Coll Cardiol (2004) 44:398–405.[Abstract/Free Full Text]
  18. Kitaoka H., Kubo T., Okawa M., et al. Left ventricular remodeling of hypertrophic cardiomyopathy—longitudinal observation in a rural community. Circ J (2006) 70:1543–1549.[CrossRef][Web of Science][Medline]
  19. Frenneaux M.P., Porter A., Caforio A.L., et al. Determinants of exercise capacity in hypertrophic cardiomyopathy. J Am Coll Cardiol (1989) 13:1521–1526.[Abstract]
  20. Sharma S., Elliott P., Whyte G., et al. Utility of cardiopulmonary exercise in the assessment of clinical determinants of functional capacity in hypertrophic cardiomyopathy. Am J Cardiol (2000) 86:162–168.[CrossRef][Web of Science][Medline]

Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?



This Article
Right arrow Abstract Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Malek, L. A.
Right arrow Articles by Ruzyllo, W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Malek, L. A.
Right arrow Articles by Ruzyllo, W.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?