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Statistics is the most advanced form of mathematics by which predictions about the future can be made with some degree of surety It is the vital cog linking biology and maths. However, since the last few decades, an abnormal man made bio-mathematical mutation is being spotted in the field of medical statistics.

Why superior scientists avoid NI trials?

Superior scientists avoid relying on non-inferiority (NI) trials due to fundamental statistical, interpretive, and ethical weaknesses that undermine rigorous evidence and patient benefit.

In superiority trials, flaws (poor adherence, dropouts) bias toward the null, conservatively protecting against false claims. NI trials reverse this: the same issues dilute differences, biasing toward falsely concluding the new treatment is “not unacceptably worse” than the active control by a pre-specified margin . Without a placebo arm, sensitivity cannot be confirmed, and the assumption remains tentative.

Key vulnerabilities In NI trials include arbitrary, manipulable margins that may permit clinically meaningful inferiority. High success rates (>85–95%, especially industry-sponsored) suggesting bias, and risks ( Biocreep) where successive approvals erode standards. “Non-inferior” does not mean equivalent .It can mask statistically significant inferiority. Reporting often deviates from guidelines, with inconsistent margin justification and analyses (ITT vs. per-protocol).

Ethically, NI designs accept potential efficacy loss for unproven gains (convenience, cost, safety) without direct proof, exposing patients unjustifiably in high-stakes areas. They place disproportionate proof burdens on de-escalation or alternatives while entrenching suboptimal standards.

A Lancet Oncology piece highlights this as “the tyranny of non-inferiority trials”:. The authors propose abandoning superiority/NI distinctions for simple “comparative” trials.

Final message

Superior scientists prefer superiority or hybrid designs, or direct comparisons of net patient-centered outcomes .They never go for the NI shortcuts driven by regulatory or commercial pragmatism.

Reference

1.Tannock IF, Buyse M, De Backer M, et al. The tyranny of non-inferiority trials. Lancet Oncol. 2024;25(10):e520-e525. doi:10.1016/S1470-2045(24)00218-3.

2.Beryl P, Vach W. Is there a danger of “biocreep” with non-inferiority trials? Trials. 2011 Dec 13;12(Suppl 1):A29. doi: 10.1186/1745-6215-12-S1-A29. PMCID: PMC3287743.

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Caution: Harsh language & Unscientific truths

It is a pattern out there, rolled out periodically in cardiac- pharma literature . It happened for Digoxin. They have been trying to do this to beta blockers for quite some time. They successfully ditched beta blockers in systemic hypertension with synthesized evidence. Mind you, BBs are the only drug that received a Nobel Prize for its invention, and its role in post-MI protection is well established.

The script is well written. Trying to ring a death knell for cheap and established medical therapeutic norms, citing lack of evidence. It is done based on some non-sensical study designs called Non-Inferiority Trials. (Tannock I, Buyse M, De Backer M et al.The tyranny of non-inferiority trials The Lancet Oncology, 25, e520-e525 Now, powerful cartels want to get rid of BBs in  post-MI ecosystem. REBOOT, REDUCE-AMI, ABYSS all were done with fixed ideas. Of course, ABYSS didn’t follow their agenda. Now, a  the latest trial has come out with a magical name SMART – DECISION.

Read this paper https://www.nejm.org/doi/full/10.1056/NEJMoa2601005

One famous statistician said, non-inferiority study concept is foundationally flawed. Hence, it is generally not worth reviewing them, as most conclusions are deemed to be wrong and not scientifically consumable. Still, looking beyond the trial design, three important flaws are obvious in SMART-DECISION’ trial , which argues for beta-blocker discontinuation after MI.

The study population is highly selected (median 4.7 years 98% revascularized; median LVEF 59%). The study advocated discontinuation among long-term accrued beneficiaries of BBs rather than typical 6–36-month post-ACS patients. Physician-driven HF hospitalization amplifies open-label bias. A wide non-inferiority margin (HR upper CI <1.4) plus low events (132 total) leave it underpowered, unable to exclude modest 15–25% harm (7.2% vs 9.0%).

Final message

In science, we need to be right first … being polite is optional.

When big science tries to corrupt our minds, what should we do? Let us continue with our conscience and follow the instinct and work for the welfare of our patients. We know the healing power of BBs. Let us be cautious and alert. Never allow wayward science to intrude upon our minds to take STUPID DECISIONS and defame the OMT in CAD.

Postamble

A newchallenge to take on

Fact : There is no published RCT that proves diuretics improve mortality and survival in heart failure.

Action requested : Let all evidence-based cardiologists withhold injections of Furosemide or Torsemide when they encounter their next patient with acute heart failure and pulmonary edema.

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PV isolation or ablation is considered as an ingenious modality in tackling chronic recurrent AF. Still, it is too invasive and complication-prone, with less than desired success rates. EPs are struggling to mitigate the adverse events. Hardware has vastly improved. We have since moved from RF , cryo , to pulse field ablations.

Whatever said, AF is a chaotic arrhythmia. When we try to take on the chaos head-on with more force, considerable damage, mostly invisible, is expected in the atrial battlefield. One such thing is post-ablation atrial tachycardia. The exact incidence is under-reported. Many times EPs don’t consider this as a complication at all. It is funny, some percieve it as a partial success as  the chaos has become less intense. The fact of the matter is, an AT can be more unpredictable and carry electrical morbidity, whike the risk of further AF always remain.

Zakeri R, Van Wagoner DR, Calkins H, The burden of proof: The current state of atrial fibrillation prevention and treatment trials. Heart Rhythm. 2017

Incidence of AT post AF ablation

Organized atrial tachycardias (ATs) occur in 5–40% of patients after catheter ablation for atrial fibrillation (AF), with the exact rate depending on the index procedure strategy, AF duration, LA size, and follow-up duration.

  • With pulmonary vein isolation (PVI) alone: Incidence is lower (5% or less). When AT occurs, it is frequently focal, most often originating from reconnected PVs
  • With additional substrate modification (linear lesions, complex fractionated atrial electrogram ablation, etc., common in persistent AF): Incidence rises to a prohibitive 20–50%.
  • Macro-reentrant ATs also occurs due to gap-related peri-mitral or roof-dependent circuits.

Final metssage

Both focal and non focal ATs  are much common after PV ablation, than we realise.Very often, they require another procedure or more intensive drugs . Realistically, the original purpose of treating the chronic AF is lost , if AF is likely to be transfomed to some other form of  AT.There is nothing called 50% chaos reduction in AF treatment.

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Ischemic Coronary artery disease is probably the most common medical ailment in humans.

It is managed by three 4 strategies by modern day cardiologists.

A.Only life style modification.

B.Intensive medical management (Also called as GDMT or OMT)

C.PCI

D CABG

Which one of the above modality is considered superior (& popular) among physicians and patients ?

No doubt, PCI is the undisputed winner for all the wrong reasons.

PCI success lies literally at the mercy GDMT. CABG has the same story to tell. While, only GDMT, has the vigor to  stand alone in style and  triumph in most CAD patients. It needs no great wisdom, to acknowledge, GDMT never gets its due respect. The problem is ,we are all  part of those guilty cardiology professionals, who silently watch the PCI,  shine  in false glory.

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A. Very Often. We don’t really  require the anatomical Information. A well performed stress test will tell us the presence and  significance of obstructive lesions .

B .Majority of CAD patients will require CAG , as we can’t rely on other non invasive  tests.

C.Atleast all ACS need CAG, but many CCS don’t need it.

D . Forget about it .It is unethical or rather blasphemy to treat CAD without knowing coronary anatomy.

Pathways to an answer.

Even acute STEMI can be managed without initial ( or even permanent) knowledge of coronary angiogram in atleast 70% of pateints.

*  It is sad truth, the modality of  standalone thrombolysis has been brutally  stigmatised and being portrayed as incomplete and Inferior form of treatment in  STEMI. It is pity , such a perception is deep rooted in many  cardiologsist’s mind inspite of the fact  great studies exists to prove treating STEMI without knowing the anatomy( ie prehospital lysis) could beat PCI consistently )

**How often we need CAG in Chornic CAD?  You know the answer . If moderen day cardiac Intervetions insist us  take a decision based on Physiology, then why do we want to know anatomy?

A stress test, technically is , equivalent to  simultaneous multivessel  FFR or iFFR . If some one crosses 10 METs  in a stress test ,  whatever the lesion subset, it can be considered net-equivalent for a normal  FFR of near unity. (No one  has tested this  hypothesis, so as of now it is junk science.) Still every experienced cardiologsist would acknowledge the truth in this.

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This pateint has

A. Single lead AAI pacemaker

B. DDD in AAI mode* (A pace V sense )

C.Single lead AAIR pacemaker

D. Can never answer this question without X ray or the implantation records.

Answer : I think, we can’t answer this question with this ECG strip. So we can only guess it is DDD, as single chamber AAI pacemaker is not in vogue , even though it is the most physiological pacemaker possible in ideal conditions.( If any one has any points to differentiate , please comment)

* A pace V sense in DDD, though  equivalent to AAI mode , can not be compared to AAI pacemaker, for the simple reason, ventricles just don’t have a lead in the later.

Final message

This post might appear as a EP parody. The purpose was different. It is sad to note AAI pacemaker might be dead , but the AAI as a mode will always be a great concept.It can beat on any day , the much hyped LBBBp in bulk of the pateints with SND in terms of physiology and synchrony.Fellows should realise single lead AAI can be most physiological , while, the DDD can become a pathological pacing , if it frequently switches to VVI mode , inspite of good AV conduction.


Part 2 : How do modern day DDD pacemakers reduce ventricle based pacing ?

Pacemaker vendors  have unique   proprietary algorithms designed to minimize unnecessary right ventricular pacing (%Vp) while maintaining atrial-based pacing (effectively mimicking AAI/R behavior) in patients with intact or intermittently preserved AV conduction (e.g., sinus node dysfunction without significant AV block). These algorithms promote intrinsic ventricular activation to avoid dyssynchrony, reduce atrial fibrillation risk, and potentially improve long-term outcomes.

There are two main categories:

  1. Mode-switching algorithms (AAI(R) ↔ DDD(R)): Operate primarily in atrial-based mode (AAI-like) with ventricular backup; switch to full DDD when AV block criteria are met.
  2. AV hysteresis / search algorithms: Stay in DDD(R) but dynamically extend the AV delay to search for and favor intrinsic conduction.

Annexure : Company brands and different modes and algorithms (Compiled by Grok)

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Link to a related post , that might add some sense to the above quote

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Getting a second opinion from another expert is a valuable option for our patients when they face a complex decision-making process, especially when a cardiac intervention is advised. No doubt, it is their fundamental rights too.But this could be hard, if the second opinion is sought regarding indication for coronary or interventional procedure.

It is much, much comfortable to concur with the original decision if it is pro -Intervention. (even if it is against your conscience). Vetoing a procedure which was advised by some big hospitals is almost impossible for cardiologists sitting at their office, however experienced they may be. This is because it is sort of going against, the mainstream and defying science as well. Both doctors and physicians are stuck.

I confront such situations often from patients following elite cardiology consults. I had been forthright and genuine and said a firm no or yes to many such procedures . I understood much later, that only a minority of the patients followed my No advice , while invariably they accepted my yes.

After much confabulations , recently, I have made some recalibarations on my values, (decent term for compromise ) despite all the ethical stuff I write in these columns. But, three things I ensure , before giving my opinion which goes against my assessment.

“This procedure is not indicated in the true scientific and moral sense, but 1.If you lack full trust,  or 2. If you are not ready to accept the risks of not doing it, or 3. If the fear (of not doing it ), would nag you constantly, then get it done as per the advice of  the big guys”.

Final message

Until we acquire the courage to express our true opinion , we certainly fall under the tag of medically incompetent.

Very soon, getting a second* or even third opinion may not really matter. Doctors are silently persuaded to follow the guidelines thursted  by  big scientific syndicates along with compulsion to go with patient wish & preference.


*Caution and clarification

Second clinical opinion for helping to arrive at a medical diagnosis  is of immense value and a great thing to do. In fact, doctors themselves ask for it when they are in doubt. This article is about second opinion regarding the appropriateness of various interventional procedures that is defining modern medicine.

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Decision making  for PCI in chronic CAD continues to be delicate. This is especially true, if the lesion is Intermediate and the plaque vulnerablity is susepcted.

How to tackle this stress positive Intermediate LAD lesion. Functional capacity good. Non-diabetic, mildly elevated lipids. Now, continuing medical management with intensive lipid control is the best possible management. (We have evidence for medical management being good even in significant 90% lesion) Above is a case report from https://www.acc.org/education-and-meetings/patient-case-quizzes/medical-therapy-for-cad

Reassurance is a revascularization equivalent

Sharing a similar experience with one of my patients in his early fifties. After getting a fairly convincing consultation, he accepted medical management. However, guided by both NI & AI, he sought a second opinion to confirm whether my assurance was indeed correct. He underwent FFR and OCT, and both he and his plaque became vulnerable. The FFR was normal. He was too intelligent to ask about the FFR – Stress test discordance, for which his cardiologist had no answer. Still, they did not advise a PCI and the decision was left to him, respecting the current patient-oriented guidelines.

The patient went home empowered but spent sleepless nights, fearing about potential fissures,  in the life sustaining fibrous cap.He believed that he was at the mercy of a 75-micron thin cap covering his plaque. In one of the anxious days,in the following week , he got admitted himself in a posh downtown cardiac center. A as per the guidelines, the patient chose his own pathway for a PCI. Cardiologists obliged piously to his wishes. Now, he feels better. He says he is happy to undergo a self prescribed stent.

I was glad, he had the courtesy to come back and showed the results. I learnt. it costed him 6 Lakhs and his insurance covered it fully. I realised , my 30 minutes reassurance was busted by the insurance card in few minutes. I wasn’t surprised.It’s okay, it’s all in the game. I learned it long ago. Fear* (either spontaneous or induced), the power to decide & affordability are the most powerful determinants of any inappropriate medical procedure.

Learning cardiology from UN & WHO

We have United Nations and WHO, the two global guardians. Any one with average intelligence will agree, these instituions can never bring either peace or health to this world.Let us ensure, the practice guidelines of cardiology doesn’t go that way. We boast ourselves, that we have a strongly evidence based vigorously scrutinized cardiology practice framework. How true it is ? Are we hiding behind pateint preference, and pushing  science to the  background ? Let us be transparent. I think it’s time, the powerful bodies like ACC/ESC should connect all the missing dots. .One important issue  is,  fear or anxiety-driven PCI, which usually overtakes other true indications.

Final message

In an ideal world , reassurance and GDMT , if properly done, should be a revascularization equivalent in most CAD patients .The  reality is, fear* prevails over reassurance, for a variety of reasons.

Postamble

*Anxiety thrives well, in an environment of uncertainty. It is mutually inclusive among both patients and physicians.However  most Professional physicians are expected to tackle it. Still many struggle. Patient : What if the block worsens? Physician: What if the patient comes back with an event and oh .. my pride and practice?  May be, physicians are not to be blamed much. I think. it is all about a unexplained,  biased human mind set. Even a death during an inapproproate Intervention is pardoned off, but an error, raising out of an appropriate medical mangment is rarely forgiven.

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How many lives are saved by ECMO in refractory cardiogenic shock following STEMI ?

A. Substantial

B. Many

C. Atleaset few

D. None

E. It may even Increase the fatality

Answer

While the popular answer swings between A to D , depending upon the level of optimism & belief system of cardiologists.

However, the correct answer is likely to be D(Ref 1) .

*While C, is quiet possible, E is very much a reality all experienced cardiologist would know.

Postamble

* My non-academic opinion is, ECMO and other MCS devices, are primarily,  “guilt-relieving or professional  pride delivering”  toolkits for the patient’s family and cardiologists, respectively.

Reference

https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(23)01607-0/abstract

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