Insert your Title here
Put your Name here eg :
Antonios Kallikourdis1 and Samuel Jacob1 Joel Dunning2
Insert your institution here e.g. :
- Department of Cardio-thoracic Surgery, Aberdeen Royal Infirmary, Aberdeen, AB25 2ZN, UK
- Department of Cardiothoracic Surgery, JamesCookUniversityHospital , Middlesbrough, UK
Put your contact details here:
Corresponding Author:
Joel Dunning
Department of Cardiac surgery
JamesCookUniversityHospital
Middlesbrough, UK
E-mail:
Tel/fax: +44-7801-548122
Word count : 1000
Summary
A best evidence topic in cardiac surgery was written accordingto a structured protocol. The question addressed was Insert your question here. Altogether more than ____ papers were found using the reportedsearch, of which ____represented the best evidence to answer theclinical question. The authors, journal, date and country ofpublication, patient group studied, study type, relevant outcomesand results of these papers are tabulated. We conclude that Insert your findings here, this is usually identical to your clinical bottom line at the end of the paper and you can cut and paste the clinical bottom line here if you wish
Key Words: review;Take MeSH words from the search strategy if you can
1-Introduction
A best evidence topic was constructed according to a structured protocol. This is fully described in the ICVTS [1]
Don’t edit this and remember to keep reference1 in
2-Three-part question
Have a go at this if you wish or I will do it: example:
In [patients undergoing a bioprosthetic aortic valve replacement] is [a stented or a stentless valve] superior [for achieving left ventricular recovery]
3-Clinical scenario
Feel free to add one of these in or I will do it.
You are at a national conference hearing about the benefits of a stentless aortic valve over a conventional stented valve. An eminent speaker from the floor then stands up and contends that there have been no definitively proven benefits for stentless valves. He continues to say that as the implantation time in these older patients is significantly higher with an associated increase in morbidity, that those who implant stentless valves outside of a clinical trial are similar to cardiologists who implant coronary stents outside of published national guidelines, and both practises should be discontinued. You resolve to check the literature yourself.
4-Search strategy
Have a go at this if you like, but I usually do this or edit it heavily, so you can also leave it if you prefer
Medline 1950 to May 2007 using OVID interface
[aortic valve replacement.mp OR exp aortic valve/] AND [Stentless.mp OR Stented.mp]
5- Search outcome
_____ papers were found using the reported search. From these ____ papers were identified. That provided the best evidence to answer the question. These are presented in table 1.
6-Results
Insert your results here AFTER you have added all your chosen papers to the table. We usually go straight in and discuss all or most of the papers and then come to conclusions. You only have 1000words for the whole paper from the Introduction to the Clinical bottom line and thus words are tight. You do not need to do a preamble or background information. Knowledge of the subject should be assumed.
Here is an example that you should delete:
Kunadian et al[2] in 2007 performed a meta-analysis of all the randomised controlled trials that we identified. They found that the effective orifice area and the mean and peak aortic valve gradients were significantly superior to the conventional stented valves used as controls across the 10 studies.
In addition they showed that at 6 months the left ventricular mass index reduced significantly more in the stentless valve group. However by 12 months the patients in the stented valve groups had caught up with the stentless valve groups in terms of mass regression and there was no longer a significant difference. No mortality or symptomatic benefits were demonstrated.
They also aggregated the times taken to perform the 2 types of operation. Overall there was a mean increase in the cross clamp time of 23 minutes and a 29 minute increase in the bypass time.
Ali et al [3] showed that, both stented and stentless bioprosthesis are associated with excellent clinical and haemodynamic outcomes 1 year after AVR. Comparable haemodynamic and LVM regression can be achieved using a second-generation stented pericardial bioprosthesis. However, in patients with reduced ventricular function preoperatively (left ventricular ejection fraction [LVEF] <60%), there was a significantly greater improvement in LVEF from baseline to 1 year in stentless valve recipients.
Perez et al [4] studied left ventricular mass index (LVMI) measured by transthoracic echocardiography and, in a subset, cardiovascular Magnetic Resonance (MR). Measurements were taken before valve replacement and at 6 and 12 months. There was a greater reduction in peak aortic velocity (P<0.001) and a greater increase in indexed effective orifice area (P<0.001) in the stentless group than in the stented group. There were no differences in clinical outcomes between the 2 valve groups after one year
Bakhtiary et al [5] compared coronary perfusion after aortic valve replacement with stented or stentless porcine bioprosthesis. Coronary flow increased in both groups significantly (P<.001) after aortic valve replacement. This increase was higher in the stentless group compared with that seen in the stented group (343 +/- 137 vs 221 +/- 66 mL/min). Left ventricular mass regression was similar in both groups.
Totaro et al and Santini et al [6, 12] targeted old patients (>70 years old) and found that the improved design of the recently introduced third-generation stented bioprosthesis allows implantation of a significantly bigger valve than with the old generation which was similar in function to a stentless valve.
On the other hand Doss et al [7] found that previously reported findings,faster and more complete regression of left ventricular mass and haemodynamic benefits of stentless valves were not reproducible
Cohan et al [8] studied echocardiographic measurements and functional status (Duke Activity Status Index) assessed at 3 and 12 months. They found that perioperative morbidity and mortality was similar between groups at 12 months postoperatively. Cardiopulmonary bypass times (CE: 118.6+/-36.3 minutes; SPV: 148.5+/-30.9 minutes; p = 0.0001) and aortic cross-clamp times (CE: 95.4+/-28.6 minutes; SPV: 123.6+/-24.1 minutes; p = 0.0001) were significantly prolonged in the SPV group,
Maselli et al [9] studied the effect of four different types of prosthetic aortic valves on time course and extent of regression of left ventricular hypertrophy. They found that stentless or homograft aortic valve produces more complete or at least faster regression of left ventricular hypertrophy.
The same result was achieved by Walther et al [10]. They found that regression of left ventricular hypertrophyoccurs in all patients after aortic valve replacement but isenhanced after stentless valve implantation.
Williams et al [11] studied left ventricular mass using magnetic resonance imaging (MRI) at 1 week, 6 months, and 32 months. At 32 months, measurement in diastole showed a reduction of 38% (P<.01) in the stentless group compared with 20% (P = ns) in the stented group, and measurements in systole showed a 23% (P<.01) and 13% (P = ns) reduction, respectively. This study confirms that a larger stentless valve can be implanted into a given size of aortic annulus with superior residual aortic valve gradients.
7. Clinical bottom line
This should be a quick and catchy clinical bottom line, hopefully with strong recommendations. I really don’t like the words ‘further research is needed’, please just make a conclusion based on your Best Evidence.
You can cut and paste this into the conclusion of the abstract
Here is an example
Stentless valves allow a larger effective orifice area valve to be implanted with a lower mean and peak aortic gradient post-operatively. At 6 months several studies and a meta-analysis have shown superior left ventricular mass regression in the stentless valve groups. However by 12 months the stented valve groups catch up in terms of mass regression and this significance disappears. No clinical benefits in terms of symptoms or mortality have so far been shown. On average a stentless valve requires a 23 minute longer cross-clamp time and a 29 minute longer bypass time.
References
References should go before the table. Make sure that all authors are included and not just the first 3 or 6 wih an et al. The format is as below :
[1] Dunning J, Prendergast B, Mackway-Jones K. Towards evidence-based medicine in cardiothoracic surgery: best BETS. Interact CardioVasc Thorac Surg 2003;2:405-409.
[2] Kunadian B, Thornley AR, de Belder MA, Hunter S, Kendall SWH, Graham R, Stewart M, Thambyrajah J, Dunning J. A Meta-Analysis of Valve Haemodynamics and Left Ventricular Mass Regression for Stentless Versus Stented Aortic Valves. (Ann Thorac Surg ;accepted for publication March 2007)
[3] Ali A, Halstead JC, Cafferty F, Sharples L, Rose F, Coulden R, Lee E, Dunning J, Argano V, Tsui S. Are stentless valves superior to modern stented valves? A prospective randomised trial. Circulation 2006;114:I535– 40.
[4] Perez de Arenaza D, Lees B, Flather M, Nugara F, Husebye T, Jasinski M, Cisowski M, Khan M, Henein M, Gaer J, Guvendik L, Bochenek A, Wos S, Lie M, Van Nooten G, Pennell D, Pepper J,. Randomised comparison of stentless versus stented valves for aortic stenosis: effects on left ventricular mass. Circulation 2005;112:2696 –702.
[5] Bakhtiary F, Schiemann M, Dzemali O, Wittlinger T, Doss M, Ackermann H, Moritz A, Kleine P. Stentless bioprosthesis improve postoperative coronary flow more than stented prostheses after valve replacement for aortic stenosis. J Thorac Cardiovasc Surg 2006;131:883– 8.
[6] Totaro P, Degno N, Zaidi A, Youhana A, Argano V. Carpentier-
Edwards PERIMOUNT Magna bioprosthesis: a stented valve with stentless performance? J Thorac Cardiovasc Surg 2005; 130:1668 –74.
[7]. Doss M, Martens S, Wood JP, Aybek T, Kleine P, Wimmer Greinecker G, Moritz A. Performance of stentless versus stented aortic valve bioprosthesis in the elderly patient: a prospective randomised trial. Eur J Cardiothorac Surg 2003;23:299 –304.
[8]. Cohen G, Christakis GT, Joyner CD, Morgan CD, Tamariz M, Hanayama N, Mallidi H, Szalai JP, Katic M, Rao V, Fremes SE, Goldman BS. Are stentless valves haemodynamically superior to stented valves? A prospective randomised trial. Ann Thorac Surg 2002;73:767–75.
[9]. Maselli D, Pizio R, Bruno LP, Di Bella I, De Gasperis C. Left ventricular mass reduction after aortic valve replacement: homografts, stentless and stented valves. Ann Thorac Surg 1999;67:966 –71.
[10]. Walther T, Falk V, Langebartels G, Kruger M, Bernhardt U, Diegeler A, Gummert J, Autschbach R, Mohr FW. Prospectively randomised evaluation of stentless versus conventional biological aortic valves: impact on early regression of left ventricular hypertrophy. Circulation 1999;100(19 suppl): II6 –10.
[11]. Williams RJ, Muir DF, Pathi V, MacArthur K, Berg GA.. Randomised controlled trial of stented and stentless aorticbioprotheses: hemodynamic performance at 3 years. Semin Thorac Cardiovasc Surg 1999;11:93–7.
[12]. Santini F, Bertolini P, Montalbano G, Vecchi B, Pessotto R, Prioli A, Mazzucco A. Hancock versus stentless bioprosthesis for aortic valve replacement in patients older than 75 years. Ann Thorac Surg 1998;66:S99 –103.
You should always start doing your paper here. Don’t do anything else until the table is finished.
With regard to the table do not cut and paste long passages from the abstract. Try to find the key 1 to 4 outcomes, then put in the actual figures that the papers report. Try not to use the words X was significantly higher than Y.
Try to say
X mean 34 , SD 20,
Y mean 40 SD 10,
p=0.43
Obviously if you are putting in a guideline you will have to put in their text. This is okay.
Any queries just fill in the table and put in a query in red and send it to me
Cut out the example date here and paste your own in:
Table 1: Best Evidence Papers
Author, date and country, Study type (level of Evidence /Patient group
/ Outcomes / Key results / CommentsDunning et al, 2007
Ann Thorac Surg
UK [2]
Meta analysis
(level 1a) / Ten studies were identified that included 919
patients in which the Freedom (Sorin Biomedica Cardio,
Via Crescentino, Italy), Freestyle (Medtronic, Minneapolis,
MN), Prima Plus (Edwards Life Sciences,
Irvine, CA) and the Toronto and Biocor (St Jude
Medical, St. Paul, MN) valves were used / - Peak gradient post-operatively / Stentless valve mean difference 5.80mmHg (4.69 to 6.90) better than stented valves / This meta-analysis showed that stentless
aortic valves provide an improved level of left ventricular
mass regression at 6 months, reduced aortic gradients,
and an improved effective orifice area index, at the
expense of times that were 23 minutes longer for cross clamp and a 29 minutes longer for bypass. this improvement disappeared
after 12 months
Left ventricular mass index / At 6 months
Weighted mean difference; 6.42, [95% CI 1.21 to 11.63] in favour of stentless valve
12 months WMD, 1.19; [95% CI, -4.15 to 6.53], no significant difference
Cross clamp time / Cross clamp time 23 min longer
Bypass time / Bypass time 29 mins longer