Choosing the Right Blockages to Fix After a Heart Attack: The AIR-STEMI Trial

Table of Contents

• Key Points
• Why this research matters
• How the study was designed
• Who could join the study
• How patients were assigned to a treatment strategy
• The two treatment strategies compared
• Outcomes the researchers measured
• How the data were analyzed
• Patient characteristics and enrollment results
• Procedural details: what actually happened during treatment
• Primary finding: fewer major events with physiology-guided treatment
• Secondary results: heart attacks, strokes, and repeat procedures
• Safety results: kidney injury and major bleeding
• What this means for patients
• Limitations of the study
• Practical recommendations
• Frequently Asked Questions
• Source Information

Key Points

• In the AIR-STEMI trial of 1,823 patients, functional coronary angiography guided which nonculprit blockages to stent after STEMI.
• Treating only blockages with an estimated FFR of 0.80 or less reduced major heart events compared with visually guided stenting of all narrow arteries.
• The physiology-guided strategy cut heart attacks by about half and lowered repeat procedures, kidney injury, and total contrast dye use.
• About 38 percent of patients in the physiology-guided group received no extra nonculprit stent, yet their outcomes were still better overall.
• Patients should ask whether functional coronary angiography will be used to decide if additional blockages actually need stents after a heart attack.

Why this research matters

When a patient arrives at the hospital with a STEMI, doctors usually open the completely blocked "culprit" artery as quickly as possible. But roughly one in two STEMI patients also has multivessel coronary artery disease—meaning other heart arteries are narrowed by plaque. Treating those additional arteries during the same hospital stay is called complete coronary-artery revascularization, and it is now considered the standard of care.

The problem: visual inspection of other blockages and their severity—simply looking at the angiogram (an X-ray movie of the arteries filled with dye)—is not always enough. Appearance does not show whether the narrowed artery meaningfully limits blood flow. The conventional, visual approach risks overtreating harmless blockages, which exposes patients to extra procedures, extra contrast (dye) that can harm the kidneys, and added risk of bleeding.

An alternative to visual inspection is a technique called functional coronary angiography. This computer-based method estimates the fractional flow reserve (FFR)—a measurement of whether a narrowing truly reduces blood flow to the heart muscle—directly from the angiographic images themselves. It does not require threading a pressure wire into the artery or giving drugs that stress the heart. It also provides a "pullback" analysis that helps doctors plan exactly where stents should be placed.

The AIR-STEMI investigators wanted to know if this physiology-guided approach—treating only blockages that are functionally significant—beats the traditional visual approach. This is the first large randomized trial to test that question specifically in STEMI patients with multivessel disease.

How the study was designed

This was an investigator-initiated, international, prospective, randomized superiority trial. That means it was not funded by a company seeking to sell a device, centers in more than one country participated, patients were followed forward in time, and patients were assigned randomly to one of two groups.

Patients enrolled between May 8, 2023, and January 31, 2025, at 21 hospitals in Italy and Pakistan. Overall, 6,131 patients were screened for eligibility, and 1,823 entered the trial.

The Italian Health Ministry (administered through the University Hospital of Ferrara) was the primary sponsor. A nonprofit organization, Consorzio Futuro in Ricerca, coordinated the international centers and committees, with unrestricted funding from Sahajanand Medical Technologies and Siemens Healthineers, plus software licenses from Pulse Medical Imaging Technology and Pie Medical Imaging. Importantly, the sponsors had no role in the study design, data collection, analysis, or manuscript preparation. An independent data and safety monitoring committee oversaw the trial, and an independent clinical-events committee—whose members did not know which group each patient was in—adjudicated all reported clinical events.

Who could join the study

You were eligible if you were hospitalized with a STEMI, had already undergone successful percutaneous coronary intervention (PCI) (a balloon-and-stent procedure) on the culprit lesion, and you also had multivessel disease—that is, at least one additional nonculprit artery narrowed by 50 to 99% of its normal width, with a minimum reference vessel diameter of 2.5 mm.

Key reasons you could not participate included:

• Doctors could not clearly identify the culprit lesion.
• Your nonculprit blockage was in the left main coronary artery, the major artery that supplies most of the heart's left side.
• You had planned or previous surgical bypass (CABG, coronary artery bypass grafting).
• Your life expectancy was less than 1 year.

All patients gave written informed consent before joining the trial.

How patients were assigned to a treatment strategy

Within 48 hours after successful treatment of the culprit lesion, eligible patients were randomly assigned in a 1:1 ratio to either the physiology-guided group or the conventional angiography-guided group. Randomization was done centrally through a secure web-based system, using a computer-generated allocation sequence. This means neither the patient nor the doctor could choose the group, and treatment assignments were hidden until the moment of randomization.

To keep the groups balanced, randomization was stratified according to:

• the treating center,
• sex,
• age (younger than 75 years versus 75 years or older), and
• whether the nonculprit vessel was the left anterior descending (LAD) artery or a different artery.

After randomization, this was not a blinded trial: doctors and patients knew which strategy was being used. However, the committee that later judged which events counted as outcomes did not know the group assignments.

The two treatment strategies compared

Patients in the physiology-guided group underwent functional coronary angiography for every nonculprit lesion with an estimated diameter stenosis of at least 50%. The computer estimated the FFR value; if the result was 0.80 or less, the lesion was labeled functionally important and treated with PCI, following a "virtual-PCI" plan based on the FFR pullback curve. If the functional assessment was negative (FFR value above 0.80), performing PCI on that lesion was considered a protocol violation. Analyses were performed at a central core laboratory using two validated angiography-derived FFR software systems: the Murray law–based quantitative flow ratio (AngioPlus Core) and the vessel FFR system (CAAS vFFR).

Patients in the angiography-guided group simply underwent PCI on every nonculprit lesion with an estimated stenosis of at least 50%—purely based on how the blockage looked on the angiogram, which is the traditional and still common real-world approach.

In both groups, doctors aimed to complete all revascularization during the initial hospital stay, either during the first procedure or in a staged procedure on a later day. At the treating team's discretion, complete revascularization was performed either in the initial index procedure or a separate staged procedure.

All patients received second-generation drug-eluting stents (stents coated with medication to prevent re-narrowing). There was a specific recommendation for sirolimus-eluting, biodegradable-polymer, ultrathin-strut stents (Supraflex Cruz). All patients received guideline-directed medical therapy for heart disease, and dual antiplatelet therapy (usually aspirin plus a second blood thinner such as ticagrelor or clopidogrel) was recommended for at least 12 months unless the bleeding risk was too high.

Outcomes the researchers measured

Primary outcome (efficacy): a composite of the first occurrence of any one of these events, analyzed as "time to first event":

1. death from any cause,
2. myocardial infarction (heart attack),
3. cerebrovascular accident (stroke or transient ischemic attack—a "mini-stroke"), or
4. ischemia-driven revascularization, meaning a repeat stent or bypass procedure needed because of renewed blockage symptoms.

Key secondary outcomes: the combined rate of cardiovascular death or heart attack; individual components of the primary outcome; ischemic stroke; and stent thrombosis (a blood clot forming inside the newly placed stent).

Primary safety outcome: a composite of contrast-associated acute kidney injury (kidney damage from the X-ray dye used during the procedure) or major bleeding, defined as Bleeding Academic Research Consortium (BARC) type 3, 4, or 5 bleeding—which means bleeding requiring transfusion or surgery, or fatal bleeding.

How the data were analyzed

The researchers powered the study to detect a 35% relative risk reduction with the physiology-guided strategy. They calculated that 1,718 patients would provide 80% statistical power at a two-sided alpha level of 0.05. To compensate for an expected 5% dropout rate, they aimed for at least 1,800 patients—and they enrolled 1,823.

All analyses followed the intention-to-treat principle: patients were analyzed in the group to which they were randomly assigned, whether or not they received the planned treatment. Time-to-event curves were calculated with the Kaplan–Meier method. The primary analysis used a Cox proportional-hazards model with the treatment group as the only variable. Where death could prevent the observation of other events, the researchers also used cumulative-incidence functions and Fine–Gray subdistribution hazard models. For cardiovascular death, noncardiovascular death counted as a competing event; for nonfatal outcomes, any death counted as a competing event. The proportional-hazards assumption was checked and held. There were no interim analyses and no adjustment for the multiple secondary outcomes, so confidence intervals around secondary outcomes should be interpreted cautiously.

Patient characteristics and enrollment results

A total of 1,823 patients were randomized: 913 into the physiology-guided group and 910 into the angiography-guided group. Their baseline characteristics were well balanced between groups.

Key baseline data for the physiology-guided group versus the angiography-guided group:

• Median age: 67 years (interquartile range 58–76) versus 66 years (57–75)
• Female: 223 patients (24.4%) versus 208 patients (22.9%)—overall, about 24% of the trial participants were women
• Hypertension: 638 (69.9%) versus 614 (67.5%)
• Dyslipidemia (high cholesterol): 482 (52.8%) versus 504 (55.4%)
• Diabetes: 195 (21.4%) versus 205 (22.5%)
• Current smoking: 292 (32.0%) versus 278 (30.5%)
• Previous heart attack: 87 (9.5%) versus 98 (10.8%)
• Previous PCI: 96 (10.5%) versus 105 (11.5%)
• Previous stroke or transient ischemic attack: 33 (3.6%) versus 38 (4.2%)
• Chronic kidney disease: 116 (12.7%) versus 127 (14.0%)
• Peripheral artery disease: 100 (11.0%) versus 106 (11.6%)
• Cardiac arrest at presentation: 34 (3.7%) versus 32 (3.5%)
• Killip class II or higher (signs of heart failure, up to cardiogenic shock): 192 (21.0%) versus 171 (18.8%)
• Median hemoglobin: 13.7 versus 13.9 g/dl
• Median creatinine clearance (a measure of kidney function): 85.2 versus 83.0 ml/min
• Median left ventricular ejection fraction (how well the heart pumps, as a percentage): 50.0 versus 50.0%
• Length of hospital stay: median 5.0 versus 5.5 days

Medications prescribed at discharge were also similar between groups. In the physiology-guided group compared with the angiography-guided group, aspirin was given to 890 patients (97.5%) versus 874 (96.0%), clopidogrel to 201 (22.0%) versus 195 (21.4%), ticagrelor to 623 (68.2%) versus 609 (66.9%), prasugrel to 82 (9.0%) versus 94 (10.3%), and oral anticoagulants to 86 (9.4%) versus 85 (9.3%). Most patients received an ACE inhibitor or ARB blood-pressure medication (86.5% versus 84.8%), a beta-blocker (76.5% versus 75.3%), and a statin (96.6% versus 96.5%). Additional lipid-lowering drugs included ezetimibe in 522 (57.2%) versus 525 (57.7%), bempedoic acid in 12 (1.3%) versus 18 (2.0%), and a PCSK9 inhibitor in 17 (1.9%) versus 14 (1.5%).

The assigned strategy was actually implemented in 886 patients (97.0%) in the physiology-guided group and in 871 patients (95.7%) in the angiography-guided group. Median follow-up was 17.9 months (interquartile range 12.0 to 24.0). Clinical follow-up was complete for 98.9% of the physiology group and 99.2% of the angiography group—meaning almost no one was lost from the analysis.

Procedural details: what actually happened during treatment

The two strategies changed what happened during the procedures. In the physiology-guided group, 1,332 total procedures were performed. The index procedure (the first, culprit-artery procedure) included PCI of a nonculprit vessel in only 115 of 913 patients (12.6%), while 419 staged procedures were performed, of which 397 (94.7%) included PCI of a nonculprit vessel. In the angiography-guided group, 1,590 procedures were performed, with nonculprit PCI during the index procedure in 197 of 910 patients (21.6%) and in 674 of 680 staged procedures (99.1%). The median time from the index procedure to the staged procedure was 3.0 days in the physiology-guided group versus 2.0 days in the angiography-guided group.

Artery access was through the wrist (radial artery) in about 97% of procedures in both groups. The median amount of contrast dye used was lower with physiology guidance: 180 ml versus 223 ml. The culprit vessel was most often the left anterior descending artery or right coronary artery in both groups.

The measured nonculprit vessels in the physiology group were 1,147. Their locations and complexities were similar to those in the angiography group (1,128 vessels): left anterior descending artery 41.8% versus 41.9%, circumflex artery 30.7% versus 30.3%, and right coronary artery 27.6% versus 27.7%. Median reference diameter was 3.0 mm in both groups; median percent stenosis was 80% versus 79%. The severity of stenosis in the nonculprit vessels was also comparable, with most blockages (about 6 in 10) falling into the 70–89% range.

Most importantly, in the physiology-guided group, the functional assessment succeeded in 1,132 of 1,147 vessels (98.6%); 15 vessels (1.3%) additionally required a wire-based FFR measurement because the imaging-based analysis could not be applied. The median FFR value was 0.80 (interquartile range 0.70–0.90). Based on the physiologic measurement:

• 590 of 1,147 vessels (51.4%) were classified as functionally important (FFR 0.80 or less), and
• 596 vessels (51.9%) were actually treated with PCI.

The virtual-PCI plan—derived from the FFR pullback curve—was implemented in 482 of the 596 treated lesions (80.8%). In contrast, the angiography-guided group treated virtually everything that looked narrow: PCI was performed on 1,071 of 1,128 nonculprit vessels (94.9%). This is the heart of the difference: physiology guidance avoided stenting in roughly half the arteries that the eye would have treated.

Primary finding: fewer major events with physiology-guided treatment

At the time of the primary analysis, a primary-outcome event—the first occurrence of death from any cause, heart attack, stroke, transient ischemic attack, or ischemia-driven repeat revascularization—had occurred in:

• 81 patients (8.9%)—about 9 of every 100—in the physiology-guided group, versus
• 125 patients (13.7%)—about 14 of 100—in the angiography-guided group.

The hazard ratio was 0.62 (95% confidence interval, 0.47 to 0.83; P<0.001). In plain language, patients in the physiology-guided group had roughly a 38% lower hazard (rate) of such events over time, compared with patients in the conventional angiography group. The P value below 0.001 means the probability that this difference occurred by chance is less than one in 1,000—an extremely robust result.

The number needed to treat was 21 (95% CI, 13 to 51). That means approximately 21 patients would need to be treated with the physiology-guided strategy, instead of the visual strategy, to prevent one death, heart attack, stroke, or repeat revascularization event.

Pre-specified subgroup analyses—across age, sex, diabetes, and other factors—showed that the benefit appeared consistent. Additional sensitivity analyses, including analyses that excluded procedure-related heart attacks, also supported the main result.

Secondary results: heart attacks, strokes, and repeat procedures

The secondary outcomes—the numbers below appear in the table as they were reported—also strongly favored the physiology-guided strategy, especially for heart attacks. Cardiovascular death or heart attack (combined) occurred in 52 patients (5.7%) versus 96 patients (10.5%), with a hazard ratio of 0.52 (95% CI, 0.37 to 0.73).

Looking at individual outcomes:

• Death from any cause: 36 patients (3.9%) versus 46 patients (5.1%); hazard ratio 0.77 (95% CI, 0.50 to 1.20). This difference did not reach statistical significance.
• Cardiovascular death: 20 (2.2%) versus 31 (3.4%); HR 0.64 (95% CI, 0.36 to 1.12).
• Noncardiovascular death: 16 (1.8%) versus 15 (1.6%); HR 1.07 (95% CI, 0.53 to 2.17).
• Any myocardial infarction: 35 (3.8%) versus 73 (8.0%); HR 0.47 (95% CI, 0.31 to 0.70)—about a 53% lower rate of heart attacks.
• Procedure-related heart attack: 15 (1.6%) versus 33 (3.6%); HR 0.45 (95% CI, 0.24 to 0.83).
• Spontaneous (not procedure-related) heart attack: 21 (2.3%) versus 45 (4.9%); HR 0.46 (95% CI, 0.27 to 0.77).
• Ischemic stroke: 3 (0.3%) versus 4 (0.4%); HR 0.75 (95% CI, 0.17 to 3.35). Strokes were rare; this difference could be due to chance.
• Ischemia-driven repeat revascularization: 29 (3.2%) versus 47 (5.2%); HR 0.61 (95% CI, 0.38 to 0.97).
• Stent thrombosis (clot in the stent): 6 (0.7%) versus 11 (1.2%); HR 0.54 (95% CI, 0.20 to 1.47)—again, the numbers were small, so this difference was not separately conclusive.

The reduction in heart attacks was not merely a matter of avoiding procedure-related events. Spontaneous heart attacks—events occurring on their own, away from any procedure—were also cut by more than half, which is a biologically meaningful signal that the physiology-guided strategy correctly identified dangerous, flow-limiting disease.

Safety results: kidney injury and major bleeding

The physiology-guided strategy was also, on balance, safer. The primary safety outcome—contrast-associated acute kidney injury or major bleeding (BARC type 3, 4, or 5)—occurred in 42 patients (4.6%), about 5 of every 100, in the physiology-guided group, versus 65 patients (7.1%), about 7 per 100, in the angiography-guided group. The hazard ratio was 0.63 (95% CI, 0.43 to 0.93; P=0.02).

Breaking this down:

• Contrast-associated acute kidney injury: 20 patients (2.2%) versus 36 patients (4.0%); HR 0.55 (95% CI, 0.32 to 0.94). The lower dye volume used in the physiology-guided group (median 180 ml versus 223 ml) probably helped protect the kidneys.
• Major bleeding (BARC type 3, 4, or 5): 23 patients (2.5%) versus 33 patients (3.6%); HR 0.69 (95% CI, 0.41 to 1.18). Bleeding was less frequent in the physiology-guided group, although this component by itself did not reach statistical significance.

The reduced number of procedures, shorter or deferred planned stenting, and lower contrast exposure are likely explanations for the safety benefit.

What this means for patients

For patients who have had a STEMI and are discovered to have additional blockages, this trial offers a clear, practical message: treating every visible narrowing is not the best approach. Instead, using the physiology of blood flow—estimated through functional coronary angiography—to guide which arteries are stented leads to:

• fewer major adverse events (about 5 fewer events per 100 patients over roughly 1.5 years),
• approximately half the number of heart attacks,
• fewer repeat procedures caused by renewed symptoms,
• fewer safety events, especially contrast-related kidney injury, and
• less contrast dye overall during hospitalization.

The effect was consistent across the pre-specified subgroups. That gives cardiologists confidence that most types of STEMI patients—older and younger, male and female, with and without diabetes—derive the same relative benefit from the physiology-guided strategy.

Avoiding an unnecessary stent has real downstream value. A stent, while life-saving for a critical blockage, carries risks of clotting, re-narrowing, the need for prolonged blood thinners, and procedural complications. In this trial, when the FFR estimate was above 0.80, leaving the lesion alone reduced events rather than increasing them—future heart attacks were actually less common. That is strong evidence that the eyes—even the trained eyes of an interventional cardiologist—are inferior to physiologic measurement in this setting.

The technology used here is also patient-friendly in an important sense. Functional coronary angiography required a pressure wire in only 1.3% of vessels. The whole FFR calculation was done offline (and, in future clinical practice, can be done in real time) using the same angiogram already obtained, without extra medication to stress the heart, without passing a wire across a delicate plaque, and without additional radiation.

Limitations of the study

This trial has limitations that patients should understand before drawing firm conclusions.

First, though the follow-up was complete for almost all patients, the median duration of observation was only 17.9 months. Long-term differences—whether the benefit persists, grows, or fades at 3 or 5 years—are not yet known.

Second, the trial was not blinded. Patients and doctors knew which treatment strategy was being used, which could theoretically influence later decisions such as the threshold for performing a repeat procedure. The fact that event adjudication was blinded reduces, but does not eliminate, this concern.

Third, while the primary endpoint was highly significant, some secondary endpoints—including deaths and strokes—had wide confidence intervals and small event counts. The trial could not definitively prove that the physiology-guided strategy reduces death from any cause (HR 0.77; 95% CI, 0.50 to 1.20) or cardiovascular death (HR 0.64; 95% CI, 0.36 to 1.12). The hazard ratios suggest a possible mortality benefit, but chance cannot be excluded for those specific outcomes.

Fourth, because researchers did not adjust for multiple comparisons across secondary outcomes, a finding could appear statistically significant by chance. The authors explicitly caution that the confidence intervals for secondary outcomes should not be used to infer the size of treatment effects.

Fifth, the trial was conducted at 21 experienced, high-volume centers in Italy and Pakistan. Approximately three-quarters of the participants were men. Whether results would be identical in other health-care settings, or specifically in women (who made up 24% of this population), is less certain, although subgroups appeared consistent.

Finally, the angiography-guided comparator is sometimes more aggressive than some community practice: it treated 94.9% of visually narrow vessels. That high rate of treatment is exactly the standard of care based on visual interpretation, but it may overstate the absolute benefit of physiology guidance compared with a more "conservative" physician who might already leave some moderate lesions alone. What the trial demonstrates is that functional guidance is better than a routine policy of visually guided complete revascularization.

Practical recommendations

What can patients take from this study?

1. If you are hospitalized with a heart attack and told that additional blockages exist, ask your cardiologist whether a functional assessment—such as functional coronary angiography—will be used to decide which blockages actually need stents.
2. Understand that having a blockage of 50–99% on the X-ray does not mean that stenting is always required. More than one-third (about 38%) of patients in the physiology-guided arm had no nonculprit stent placed, and these patients still did better overall than those who had all visible lesions stented.
3. If your doctor recommends leaving a moderate narrowing unstented because its measured FFR is above 0.80, the trial's results support that decision. It was associated with fewer heart attacks—not more—than stenting every narrowing would have been.
4. After any heart attack, guideline-directed medical therapy remains vital. In both groups, more than 96% of patients were discharged on aspirin and a statin, and most received a second antiplatelet drug, a beta-blocker, and an ACE inhibitor or ARB. No stenting strategy can replace these medicines.
5. The safest approach to stenting after a heart attack is still the one that targets medically appropriate lesions. The physiological approach used less dye, produced fewer kidney injuries, and resulted in fewer repeat procedures.

This is what high-quality randomized evidence looks like in modern cardiology. The AIR-STEMI trial should encourage hospitals to make functional coronary angiography a routine part of complete revascularization planning in STEMI patients with multivessel disease.

Frequently Asked Questions

After a STEMI heart attack, doctors found blockages in more than one of my heart arteries. How do they decide which additional blockages to stent?

In the AIR-STEMI trial, doctors compared two ways to choose. One used functional coronary angiography, a computer method that estimates whether a narrowing truly limits blood flow. The other used traditional visual inspection alone. Treating only blockages with reduced flow led to fewer deaths, heart attacks, strokes, or repeat procedures than stenting every visible narrowing.

What is functional coronary angiography and does it require extra wires or medications?

Functional coronary angiography estimates fractional flow reserve directly from standard angiogram images. It does not require threading a pressure wire across the blockage or giving extra drugs to stress the heart. In the AIR-STEMI trial, a pressure wire was needed for only about 1 in 100 vessels. The analysis can be done using images already taken.

If my doctor says an additional blockage has a fractional flow reserve above 0.80, is it safe to leave it without a stent?

In the AIR-STEMI trial, patients whose nonculprit blockages were left unstented because their estimated FFR was above 0.80 had fewer heart attacks and other events than patients who had every narrow-looking artery stented. About 38 percent of patients in the physiology-guided group had no additional stent placed, and they did better overall.

What were the main benefits of using functional coronary angiography after a heart attack in the AIR-STEMI trial?

Among about 1,800 patients followed for roughly 18 months, the physiology-guided approach reduced major events from about 14 per 100 to about 9 per 100. Heart attacks were about half as frequent. Repeat procedures, contrast-related kidney injury, and the amount of dye used were also lower compared with treating all visible blockages.

Did the AIR-STEMI trial show that the physiology-guided approach reduced deaths?

The trial found fewer deaths from any cause in the physiology-guided group, but that difference did not reach statistical significance. Cardiovascular death was also less frequent, yet chance could not be ruled out for those specific outcomes. The clearest benefits were fewer heart attacks and fewer repeat procedures, along with fewer safety events overall.

What were the safety results regarding the kidneys and bleeding in the AIR-STEMI trial?

The combined safety outcome of contrast-associated acute kidney injury or major bleeding happened in about 5 of 100 patients with physiology guidance versus 7 of 100 with visual guidance. Kidney injury was significantly less common, likely because less contrast dye was used. Major bleeding was also less frequent, though that difference alone was not statistically significant.

Are the AIR-STEMI results applicable to women, older adults, and people with diabetes?

The trial enrolled patients with STEMI and multivessel disease, including about 24 percent women. Pre-specified subgroup analyses across age, sex, and diabetes showed the benefit of physiology-guided treatment appeared consistent. However, most participants were men, and the trial was conducted at experienced centers in two countries, so results may differ in other health-care settings.

I had a heart attack and have several blockages. My cardiologist recommends stenting all of them. Should I get a second opinion on whether all blockages really need stents?

In a large international trial of STEMI patients with multivessel disease, routine stenting of all visually significant nonculprit blockages was compared with using functional coronary angiography, which estimates whether each narrowing truly limits blood flow. The physiology-guided approach treated only about half the blockages and led to roughly half the heart attacks, fewer repeat procedures, lower contrast dye exposure, and less kidney injury. Because the visual-angiography strategy may overtreat harmless narrowings, a second opinion can help determine whether functional assessment should guide stent decisions. Diagnostic Detectives Network provides independent expert second opinions.

Source Information

This patient-friendly article is based on peer-reviewed research originally published in The New England Journal of Medicine. Original article: "Complete Revascularization Guided by Functional Coronary Angiography in STEMI," by S. Biscaglia, A. Erriquez, I. Colaiori, and colleagues, for the AIR-STEMI Trial Investigators (published August 29, 2026; DOI: 10.1056/NEJMoa2605373). Copyright © 2026 Massachusetts Medical Society.

The original authors report relationships with device and imaging companies, including Sahajanand Medical Technologies, Pulse Medical Imaging Technology, and Pie Medical Imaging, as described in the journal article. The trial was sponsored by the Italian Health Ministry and administered by the University Hospital of Ferrara. Trial registration: ClinicalTrials.gov number, NCT05818475.