Monday, 28 December 2015
Friday, 18 December 2015
The clinicopathologic conference
The clinicopathologic conference
 |
“When
I was a medical student, clinicopathologic
conferences (CPC) were big events. A medical resident (called the presenter),
presents an unknown case, giving the history, physical examination, and all
relevant investigations, providing the results of those diagnostic tools. The
presenter does not interpret the data; rather he allows the discussant to
interpret those data. The discussant - a consultant faculty member of the
department - discusses the case based on the presented history, physical
findings, and diagnostic studies obtained. Differential diagnoses are put
forward and narrowed; the discussant is expected to adhere on a measured,
logical progression from a patient's presentation to a narrowed differential
diagnoses rather than focusing on a final diagnosis but in the end, he makes a
tentative diagnosis based on his discussion of the case before the final
diagnosis is revealed. At the end of the discussion, the audience participates
in a "question and answer" forum (usually 15 min). After discussion
of the case, the presenter (medical resident) discusses how the diagnosis is
confirmed and provides details regarding the case outcome. It is, therefore,
very important that the case is presented with clarity”.
|
Sunday, 22 November 2015
Friday, 20 November 2015
Thursday, 19 November 2015
Sunday, 8 November 2015
Saturday, 7 November 2015
Thursday, 5 November 2015
Why we see idols in the temple?
Why we see idols in the temple!
-Once upon a time, a group of people wanted to share their sin in between themselves. It was hurting the inner-self badly! Difficult to sleep with so much sin. But none agreed. They carried it to their group leader. The leader ordered to offer it to GOD. The leader also accompanied them. Everybody was very sure only God can excuse and reduce it to portable size that would no more hurt . So everybody put their visible and invisible sins into their own big big gunny bags. So did the leader. They all approached towards temple. Until then God was very much in flesh and blood,walking and talking. The gate keeper in the temple informed God about this. God requested the devotes in the temple to find suitable place to accommodate all the sins. The devotes reported that there is not space enough inside . Everywhere in the temple was filled with virtues. God was thinking what to do! People with sin and their GOD became restless! Before God could sort out, GOD and devotes in the temple campus were buried in the mud of sin.The mob poured strait those sins on the head of GOD and devotes! GOD and devotes failed to pull them out of the pond of sin. The effect of those sins were the worst! God and his devotes could not breath .They died.People returned happily. The effect of those worst sins changed GOD and devotes into idols of stone and metals overnight. Since then, neither God nor his devotes have got back their lives. None again has seen walking GOD.
Moral of the story: There is none in the world who will be able to carry your sin.
-Once upon a time, a group of people wanted to share their sin in between themselves. It was hurting the inner-self badly! Difficult to sleep with so much sin. But none agreed. They carried it to their group leader. The leader ordered to offer it to GOD. The leader also accompanied them. Everybody was very sure only God can excuse and reduce it to portable size that would no more hurt . So everybody put their visible and invisible sins into their own big big gunny bags. So did the leader. They all approached towards temple. Until then God was very much in flesh and blood,walking and talking. The gate keeper in the temple informed God about this. God requested the devotes in the temple to find suitable place to accommodate all the sins. The devotes reported that there is not space enough inside . Everywhere in the temple was filled with virtues. God was thinking what to do! People with sin and their GOD became restless! Before God could sort out, GOD and devotes in the temple campus were buried in the mud of sin.The mob poured strait those sins on the head of GOD and devotes! GOD and devotes failed to pull them out of the pond of sin. The effect of those sins were the worst! God and his devotes could not breath .They died.People returned happily. The effect of those worst sins changed GOD and devotes into idols of stone and metals overnight. Since then, neither God nor his devotes have got back their lives. None again has seen walking GOD.
Moral of the story: There is none in the world who will be able to carry your sin.
Wednesday, 4 November 2015
Sunday, 1 November 2015
Daughter is precious
Mother inspired to be in family
Sister taught the sacrifice to meet a family
Girl friend slapped the unfit to own a family
Wife proved none can afford a family
Daughter filled everything with love in family
Sister taught the sacrifice to meet a family
Girl friend slapped the unfit to own a family
Wife proved none can afford a family
Daughter filled everything with love in family
Saturday, 31 October 2015
Saturday, 24 October 2015
Wednesday, 21 October 2015
Friday, 16 October 2015
The solubility of potassium chloride at 20 degree celsius is 34.7g in 100g of water
The solubility of potassium
chloride at 20 degree celsius is 34.7g in 100g of water.The density of the
solution is 1.3g/ml.What is the w/v percentage of potassium chloride in the
solution
Answer
Step-1: Let volume of the solution be V ml which contains 34.7gm of KCL and 100gm of water ?
Step-2: Density= (34.7+100)/V = 1.3gm/ml
Answer
Step-1: Let volume of the solution be V ml which contains 34.7gm of KCL and 100gm of water ?
Step-2: Density= (34.7+100)/V = 1.3gm/ml
Step-3:134.7=1.3V
Step-4:V=134.7/1.3 ml=103.61ml
Step-5:%w/v=mass of KCl in 100 ml
of solution
Step-6:103.61 ml of KCL contains
34.7 g of KCl
Step-7:100ml of KCL contains=34.7/103.61x100=33.49gm/100
ml
Tuesday, 11 August 2015
Who is happy??
A Crow was absolutely satisfied in life.
But one day he saw a swan...
This swan is so white and I am so black...crow thought.
This swan must be the happiest bird in the world.
He expressed his thoughts to the swan.
"Actually," the swan replied,
"I was feeling that I was the happiest bird around until I saw a parrot, which has two colors.
I now think the parrot is the happiest bird in creation."
The crow then approached the parrot.
The parrot explained,
"I lived a very happy life—until I saw a peacock.
I have only two colors, but the peacock has multiple colors."
The crow then visited a peacock in the zoo and saw that hundreds of people had gathered to see him.
After the people had left,
The crow approached the Peacock..
Dear Peacock,
You are so beautiful.
Every day thousands of people come to see you.
When people see me,
they immediately shoo me away.
I think you are the happiest bird on the planet.
The peacock replied,
I always thought that I was the most beautiful and happy bird on the planet.
But because of my beauty,
I am entrapped in this zoo.
I have examined the zoo very carefully, and I have realized that the crow is the only bird not kept in a cage.
So for past few days I have been thinking that if I were a crow,
I could happily roam everywhere.
That's our problem too.
We make unnecessary comparison with others and become sad.
We don't value what God has given us.
This all leads to the vicious cycle of unhappiness.
Value the things God has given us.
Learn the secret of being happy and discard the comparison which leads only to unhappiness..
Thursday, 21 May 2015
A relationship that time could not break
A stranger who comes for gain ,leaves
A stranger who comes for gain and to give ,leaves
A stranger who comes to give ,lasts forever
A stranger who comes for gain and to give ,leaves
A stranger who comes to give ,lasts forever
 |
| Relationship that time could not break |
Monday, 18 May 2015
Monday, 11 May 2015
You can not take wild from animal
A folk story
A wood cutter brought a innocent tiny beer pulp from forest as the baby was crying helplessly after the mother shot dead by jungle mafia.Baby bear grew .Most of the neighbor suggested to leave the beast in forest.The bear lover could not see any reason why he should do it?One day,he suddenly woke up from a nice nap with severe pain in face.He was bleeding profusely from nose ,The watchful wife nearby reasoned:to kill a fly, sitting on your nose ,your lover has just plucked your nose.It is high time to give him up.Owner ,very much convinced the nightmare and conveyed the neighbors "You can take animal from wild but you can not take wild from animal"
A wood cutter brought a innocent tiny beer pulp from forest as the baby was crying helplessly after the mother shot dead by jungle mafia.Baby bear grew .Most of the neighbor suggested to leave the beast in forest.The bear lover could not see any reason why he should do it?One day,he suddenly woke up from a nice nap with severe pain in face.He was bleeding profusely from nose ,The watchful wife nearby reasoned:to kill a fly, sitting on your nose ,your lover has just plucked your nose.It is high time to give him up.Owner ,very much convinced the nightmare and conveyed the neighbors "You can take animal from wild but you can not take wild from animal"
Friday, 1 May 2015
Monday, 27 April 2015
Sunday, 26 April 2015
WPW syndrome associated with left sided posterior-lateral bundle of Kent
 |
| Kent bundle is located in the left posterior lateral aspect of left ventricle because delta wave and QRS are positive in V1 &V2 and there is left axis deviation |
Friday, 24 April 2015
You can't outrun a bad diet
"It's time to wind back the harms caused by the junk food industry's public relations machinery. Let's bust the myth of physical inactivity and obesity," they write. "You can't outrun a bad diet."
http://www.cbsnews.com/news/the-key-to-weight-loss-you-cant-outrun-a-bad-diet/
http://www.cbsnews.com/news/the-key-to-weight-loss-you-cant-outrun-a-bad-diet/
Thursday, 23 April 2015
Tuesday, 21 April 2015
Sunday, 19 April 2015
Beauty, the body, and identity
Beauty, the body, and identity
The body is our closest ally and
our greatest enemy. We inhabit it
and cannot escape it. We wake with
it and we die with it. The body will
kill us, even when our minds resist.
The body is a source of our shame
as well as an expression of our pride.
Our body is our primordial identity.
But still we ask: who are we, what
are we? Although it would be foolish
to think that ancient Greek art
can provide simple answers to our
questions, it certainly can provoke
thoughts and responses that will
illuminate these questions in
extraordinary ways.
Beauty, the body, and identity - The Lancet
-Richard Horton
Email:richard.horton@lancet.com
Wednesday, 15 April 2015
Tuesday, 14 April 2015
Is your heart age older than you? My heart age is 34, what’s yours?
http://www.heartage.me/your-heart-age/you
Did you know that your heart age can be older than your actual age? More than 6 million people have already taken our test around the world. Join them today to find out your heart age and how to improve it.
Did you know that your heart age can be older than your actual age? More than 6 million people have already taken our test around the world. Join them today to find out your heart age and how to improve it.
Primary mitral regurgitation
1.Define :Primary MR is characterized by pathology of the valvular apparatus, to include the leaflets, chordae, papillary muscles, or annulus. Secondary regurgitation typically results from left ventricular (LV) dysfunction, which alters LV wall motion and geometry, tethering the leaflets and causing malcoaptation. The amount of regurgitant volume that may cause adverse outcomes differs between primary and secondary MR; amounts that would be considered only “moderate” in a case of primary MR may be “severe” when the etiology is secondary.
2.Severe primary mitral regurgitation :The rule of 567=5:Regurgitation fraction is 50% or more;6 :Regurgitation volume is 60 ml or more and 7:Vena contracta is 0.7 or more .
3.Acute severe may be faintly audible or not at all audible because of very high left atrial pressure.There during PBMV auscultate for residual MS but not for appearance of severe MR (Pressure tracing,ECHO and symptom would tell).
Severe MR[Rule of 4,5,6,7]
Vena contracta of the mitral regurgitation jet ≥0.7 cm
Regurgitant volume ≥60 ml
Regurgitant fraction ≥50%
Effective regurgitant orifice area of ≥0.4 cm2
LV dilation
2.Severe primary mitral regurgitation :The rule of 567=5:Regurgitation fraction is 50% or more;6 :Regurgitation volume is 60 ml or more and 7:Vena contracta is 0.7 or more .
3.Acute severe may be faintly audible or not at all audible because of very high left atrial pressure.There during PBMV auscultate for residual MS but not for appearance of severe MR (Pressure tracing,ECHO and symptom would tell).
Severe MR[Rule of 4,5,6,7]
Vena contracta of the mitral regurgitation jet ≥0.7 cm
Regurgitant volume ≥60 ml
Regurgitant fraction ≥50%
Effective regurgitant orifice area of ≥0.4 cm2
LV dilation
Alcohol is not for good
The occurrence of cardiovascular disease (CVD) events remains the number one cause of death worldwide. Therefore, the definition of potentially modifiable targets to reduce the incidence of CVD remains a key public health priority. While excessive alcohol consumption is a major contributor to the occurrence of non-cardiovascular morbidity and mortality, a large body of evidence suggests that individuals consuming low to moderate amounts of alcohol have a lower risk of suffering from some, but not all CVD outcomes. For example, previous studies found a linear inverse relationship between alcohol consumption and the occurrence of ischaemic heart disease or myocardial infarction, and a U-shaped association of alcohol consumption with the occurrence of sudden cardiac death. In contrast, low to moderate amounts of alcohol intake have not been found to be protective for the incidence of atrial fibrillation or stroke.
Monday, 13 April 2015
Saturday, 11 April 2015
Friday, 10 April 2015
Thursday, 9 April 2015
Wednesday, 8 April 2015
Classification of endoleaks after endovascular aneurysm repair.
(Ib) perigraft flow occurring distally, and (Ic) perigraft flow around
an iliac artery occlusion device.
Type II(Branch):Branch arteries back-bleed because of collateral flow. These
endoleaks include (IIa) back-bleeding inferior mesenteric artery
and (IIb) back-bleeding lumbar artery.
Type III :Flow persists between the segments of a modular graft and
include (IIIa) leaks between iliac limbs or an iliac limb and main
body component and (IIIb) leaks between main body components.
Type IV(Porosity) :Flow is present through endograft material (graft porosity).
Type V(Endotension) :(V), Persistent or recurrent pressurization of the
aortic aneurysm exists in the absence of demonstrable endoleak.
References
Eliason JL, Upchurch GR Jr. Endovascular abdominal aortic aneurysm
repair. Circulation. 2008;117:1738–1744.
Tuesday, 7 April 2015
Left pulmonary artery hypoplasia is associated with Tetralogy of Fallot's
 |
| Large patent doctus arteriosus supporting blood supply to left lung |
 |
| A large collateral from descending thoracic aorta supporting left lung blood supply |
 |
| Diminutive pulmonary artery due to hypoplasia with narrowed left pulmonary artery |
Sunday, 5 April 2015
Aortic arch anatomy variations in human
The aortic arch can be characterized into three types based on the vertical distance from the origin of the innominate artery to the top of the arch
Type A-. A type 1 arch has a distance that is less than one times the diameter of the left common carotid artery (CCA). A type 2 arch originates from one to two CCA diameters from the top of the arch, and a type 3 arch originates more than 2 CA diameters from the top of the arch
Type B and C -Left common carotid artery from innominate artery
Type D-True bovine arch
Type E-Arteria lusoria
Saturday, 4 April 2015
Cardiac resynchronization therapy
Before CRT -
1. AHA criteria for CRT indication -OK
2. Coronary Angiogram to rule out ischemic left ventricular dysfunction [CAG/SPECT/CMRI]
4. Coronary sinus angiogram in AP/RAO/LAO view to find suitable coronary vein tributary to place the left ventricular lead and antecubetal vein angiogram to rule anomalous venous system on the day
1.2
On the day of CRT
1. Keep coronary angiogram on screen of AP view
2. TPI in place through transfemoral
3. Scrub
4. Left infraclavicular local anaesthesia
5. Insert 3 short guide wire into IVC
6. Introduce 10Fr coronary sinus sheath
7. Repeat coronary sinus venogram to find suitable LV tributary if already documented view is not well profiled
LV lead insertion
7. Release one lead for introduce 10Fr sheath for left ventricular lead
8. Take JR -4Fr through 10Fr sheath and enter 10Fr sheath into coronary sinus
9. Advance 4Fr JR into the suitable left coronary sinus tributary [upper most and left most]
10. Remove terumo and JR keeping 10Fr in CS
11. Take reverse barman or 20ml syringe, do a coronary sinus venogram to find a suitable tributary
11. Load PTCA wire into LV lead and shape the tip of PTCA wire by giving double bend
12. Introduce LV lead into a pilable sheath then introduce same into 10Fr
13. Advance PTCA wire into suitable tributary
14. Move the LV lead into the above
15. Check threshold and if ok
16. Remove the pilable 10Fr and release its hub through sleeve of LV lead and lead screwing end
17. Secure LV lead into pocket using proline 2-0
18. Then introduce RV tin lead
19. Introduce RA appendage lead
20. Test each one for threshold, cough and deep inspiration and diaphragm contraction
21, Connect lead CRT device -top to RAA, MIDDLE-rv and bottom-lv, never forget to check lead connection proper also by their assigned number
22. Most of the procedure like PPI 23. Keep lead loops behind the PG by that you would not cut them on next visit
24. Keep the connecting side to left and top and the trade mark on PG should look anterior
25. Fix PG to both upper and lower part inside.
26. Complete like PPI
After CRT
-Immediate Chest X-Ray to rule out pneumothorax
-Watch for pocket hemotoma at earliest
-
1. AHA criteria for CRT indication -OK
2. Coronary Angiogram to rule out ischemic left ventricular dysfunction [CAG/SPECT/CMRI]
4. Coronary sinus angiogram in AP/RAO/LAO view to find suitable coronary vein tributary to place the left ventricular lead and antecubetal vein angiogram to rule anomalous venous system on the day
1.2
On the day of CRT
1. Keep coronary angiogram on screen of AP view
2. TPI in place through transfemoral
3. Scrub
4. Left infraclavicular local anaesthesia
5. Insert 3 short guide wire into IVC
6. Introduce 10Fr coronary sinus sheath
7. Repeat coronary sinus venogram to find suitable LV tributary if already documented view is not well profiled
LV lead insertion
7. Release one lead for introduce 10Fr sheath for left ventricular lead
8. Take JR -4Fr through 10Fr sheath and enter 10Fr sheath into coronary sinus
9. Advance 4Fr JR into the suitable left coronary sinus tributary [upper most and left most]
10. Remove terumo and JR keeping 10Fr in CS
11. Take reverse barman or 20ml syringe, do a coronary sinus venogram to find a suitable tributary
11. Load PTCA wire into LV lead and shape the tip of PTCA wire by giving double bend
12. Introduce LV lead into a pilable sheath then introduce same into 10Fr
13. Advance PTCA wire into suitable tributary
14. Move the LV lead into the above
15. Check threshold and if ok
16. Remove the pilable 10Fr and release its hub through sleeve of LV lead and lead screwing end
17. Secure LV lead into pocket using proline 2-0
18. Then introduce RV tin lead
19. Introduce RA appendage lead
20. Test each one for threshold, cough and deep inspiration and diaphragm contraction
21, Connect lead CRT device -top to RAA, MIDDLE-rv and bottom-lv, never forget to check lead connection proper also by their assigned number
22. Most of the procedure like PPI 23. Keep lead loops behind the PG by that you would not cut them on next visit
24. Keep the connecting side to left and top and the trade mark on PG should look anterior
25. Fix PG to both upper and lower part inside.
26. Complete like PPI
After CRT
-Immediate Chest X-Ray to rule out pneumothorax
-Watch for pocket hemotoma at earliest
-
Friday, 3 April 2015
Wednesday, 1 April 2015
Five follow up result for TAVI is comparable to surgery in high risk group
SAN DIEGO — In this video, Steven R. Bailey, MD, chief of cardiology at the University of Texas Health Sciences Center and Cardiology Today's Intervention Editorial Board member, discusses results from three late-breaking trials evaluating percutaneous valve technology presented at the American College of Cardiology Scientific Sessions.
He said that the 5-year results from PARTNER 1, 2-year data from CoreValve High Risk and 30-day from the PARTNER II S3 trials consistently indicate the benefits of transcatheter aortic valve replacement systems.
In PARTNER 1, researchers evaluated inoperable and operable patients, and found that TAVR recipients "feel better, live longer and live better" with a lower cost of care, Bailey said. He added that the 5-year data suggest continued valve performance without degeneration — and, in fact, that hemodynamics in the valve area were improved compared with surgery. The similar outcomes observed between surgery and TAVR recipients allow for confidence that TAVR is a viable alternative treatment, even among high-risk patients, Bailey said.
The CoreValve High Risk study compared the self-expanding transcatheter valve (CoreValve, Medtronic) with surgery, and the researchers observed better outcomes with the CoreValve at both 1 year and 2 years. Bailey said these results were "incredibly exciting," and stressed that these improved outcomes were present across all patient subtypes, regardless of age, sex, diabetes status or surgical risk.
The PARTNER II S3 trial evaluated 30-day outcomes from TAVR with the Sapien 3 system (Edwards Lifesciences) compared with earlier-generation devices. Bailey said there was a significant improvement in mortality and significant decrease in leak around the valve, which correlates with long-term outcomes. He added that these results suggest "significant progress" with the new TAVR technologies, which will continue to improve over time and offer further benefit for patients.
http://www.healio.com/cardiology/intervention/news/online/%7B9cb06d31-1b8a-45e9-a97d-c89f3527cc36%7D/video-results-from-three-trials-suggest-significant-progress-for-tavr-technology
He said that the 5-year results from PARTNER 1, 2-year data from CoreValve High Risk and 30-day from the PARTNER II S3 trials consistently indicate the benefits of transcatheter aortic valve replacement systems.
In PARTNER 1, researchers evaluated inoperable and operable patients, and found that TAVR recipients "feel better, live longer and live better" with a lower cost of care, Bailey said. He added that the 5-year data suggest continued valve performance without degeneration — and, in fact, that hemodynamics in the valve area were improved compared with surgery. The similar outcomes observed between surgery and TAVR recipients allow for confidence that TAVR is a viable alternative treatment, even among high-risk patients, Bailey said.
The CoreValve High Risk study compared the self-expanding transcatheter valve (CoreValve, Medtronic) with surgery, and the researchers observed better outcomes with the CoreValve at both 1 year and 2 years. Bailey said these results were "incredibly exciting," and stressed that these improved outcomes were present across all patient subtypes, regardless of age, sex, diabetes status or surgical risk.
The PARTNER II S3 trial evaluated 30-day outcomes from TAVR with the Sapien 3 system (Edwards Lifesciences) compared with earlier-generation devices. Bailey said there was a significant improvement in mortality and significant decrease in leak around the valve, which correlates with long-term outcomes. He added that these results suggest "significant progress" with the new TAVR technologies, which will continue to improve over time and offer further benefit for patients.
http://www.healio.com/cardiology/intervention/news/online/%7B9cb06d31-1b8a-45e9-a97d-c89f3527cc36%7D/video-results-from-three-trials-suggest-significant-progress-for-tavr-technology
Use of IABP was not found to improve mortality among patients with acute myocardial infarction in the RCTs
Intra-aortic Balloon Pump Therapy for Acute Myocardial Infarction:A Meta-analysis
http://archinte.jamanetwork.com/article.aspx?articleID=2210888
Importance Intra-aortic balloon pump (IABP) therapy is a widely used intervention for acute myocardial infarction with cardiogenic shock. Guidelines, which previously strongly recommended it, have recently undergone substantial change.
Objective To assess IABP efficacy in acute myocardial infarction.
Data Sources Human studies found in Pubmed, Embase, and Cochrane libraries through December 2014 and in reference lists of selected articles. Search strings were “myocardial infarction” or “acute coronary syndrome” and “intra-aortic balloon pump” or “counterpulsation.”
Study Selection Randomized clinical trials (RCTs) and observational studies comparing use of IABP with no IABP in patients with acute myocardial infarction.
Data Extraction and Synthesis Two reviewers independently extracted the data, and risk of bias in RCTs was assessed using the Cochrane risk of bias tool. We conducted separate meta-analyses of the RCTs and observational studies. Data were quantitatively synthesized using random-effects meta-analysis.
Main Outcomes and Measures Thirty-day mortality.
Results There were 12 eligible RCTs randomizing 2123 patients. In the RCTs, IABP use had no statistically significant effect on mortality (odds ratio [OR], 0.96 [95% CI, 0.74-1.24]), with no significant heterogeneity among trials (I2 = 0%; P = .52). This result was consistent when studies were stratified by the presence (OR, 0.94 [95% CI, 0.69-1.28]; P = .69, I2 = 0%) or absence (OR, 0.98 [95% CI, 0.57-1.69]; P = .95, I2 = 17%) of cardiogenic shock. There were 15 eligible observational studies totaling 15 530 patients. Their results were mutually conflicting (heterogeneity I2 = 97%; P < .001), causing wide uncertainty in the summary estimate for the association with mortality (OR, 0.96 [95% CI, 0.54-1.70]). A simple index of baseline risk marker imbalance in the observational studies appeared to explain much of the heterogeneity in the observational data (R2meta = 46.2%; P < .001).
Conclusions and Relevance :Use of IABP was not found to improve mortality among patients with acute myocardial infarction in the RCTs, regardless of whether patients had cardiogenic shock. The observational studies showed a variety of mutually contradictory associations between IABP therapy and mortality, much of which was explained by the differences between studies in the balance of risk factors between IABP and non-IABP groups.
http://archinte.jamanetwork.com/article.aspx?articleID=2210888
Importance Intra-aortic balloon pump (IABP) therapy is a widely used intervention for acute myocardial infarction with cardiogenic shock. Guidelines, which previously strongly recommended it, have recently undergone substantial change.
Objective To assess IABP efficacy in acute myocardial infarction.
Data Sources Human studies found in Pubmed, Embase, and Cochrane libraries through December 2014 and in reference lists of selected articles. Search strings were “myocardial infarction” or “acute coronary syndrome” and “intra-aortic balloon pump” or “counterpulsation.”
Study Selection Randomized clinical trials (RCTs) and observational studies comparing use of IABP with no IABP in patients with acute myocardial infarction.
Data Extraction and Synthesis Two reviewers independently extracted the data, and risk of bias in RCTs was assessed using the Cochrane risk of bias tool. We conducted separate meta-analyses of the RCTs and observational studies. Data were quantitatively synthesized using random-effects meta-analysis.
Main Outcomes and Measures Thirty-day mortality.
Results There were 12 eligible RCTs randomizing 2123 patients. In the RCTs, IABP use had no statistically significant effect on mortality (odds ratio [OR], 0.96 [95% CI, 0.74-1.24]), with no significant heterogeneity among trials (I2 = 0%; P = .52). This result was consistent when studies were stratified by the presence (OR, 0.94 [95% CI, 0.69-1.28]; P = .69, I2 = 0%) or absence (OR, 0.98 [95% CI, 0.57-1.69]; P = .95, I2 = 17%) of cardiogenic shock. There were 15 eligible observational studies totaling 15 530 patients. Their results were mutually conflicting (heterogeneity I2 = 97%; P < .001), causing wide uncertainty in the summary estimate for the association with mortality (OR, 0.96 [95% CI, 0.54-1.70]). A simple index of baseline risk marker imbalance in the observational studies appeared to explain much of the heterogeneity in the observational data (R2meta = 46.2%; P < .001).
Conclusions and Relevance :Use of IABP was not found to improve mortality among patients with acute myocardial infarction in the RCTs, regardless of whether patients had cardiogenic shock. The observational studies showed a variety of mutually contradictory associations between IABP therapy and mortality, much of which was explained by the differences between studies in the balance of risk factors between IABP and non-IABP groups.
Thursday, 26 February 2015
Ban on the use of P values in statistics
P values are widely used in science to test null hypotheses. For example, in a medical study looking at smoking and cancer, the null hypothesis could be that there is no link between the two. The closer to zero the P value gets, the greater the chance the null hypothesis is false; many researchers accept findings as ‘significant’ if the P value comes in at less than 0.05. But P values are slippery, and sometimes, significant P values vanish when experiments and statistical analyses are repeated (see Nature 506, 150–152; 2014).
http://www.nature.com/news/scientific-method-statistical-errors-1.14700
http://www.nature.com/news/scientific-method-statistical-errors-1.14700
Tuesday, 24 February 2015
Monday, 23 February 2015
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