Severe graft dysfunction kills by multi-organ failure and infection — and the percentages hide it.
Cause of death is recorded for 98% of deaths in the graded cohort. Read as shares, infection looks less important in severe PGD than in recipients without it. Read as rates, it kills nearly twice as many of them. Both numbers are correct; only one answers the question.
Source: OPTN/UNOS STAR, Dec 2025 release · 4,845 deaths among bilateral lung recipients with a derivable 72-hour PGD grade; cause recorded for 4,756 (98.2%). Follow-up landmarked at day 3.
+30excess multi-organ-failure deaths per 1,000
Within one year, severe PGD adds 29.6 multi-organ-failure deaths, 18.9 infection deaths and 18.0 graft-failure deaths per 1,000 recipients, against recipients with no PGD.
01 · The excess
What severe PGD adds, cause by cause
Deaths per 1,000 recipients at risk in the first year, severe minus no PGD. This is the quantity the question asks for: not what the group dies of, but how much more of it they die.
Excess first-year deaths per 1,000 at risk
Multi-organ failure is the discriminating cause. It runs 5.2 per 1,000 in recipients without PGD and 34.8 in severe PGD — a near sevenfold difference, and the largest single contributor to the first-year excess. Graft failure roughly quadruples (6.7 to 24.7). Infection, already the commonest cause in every group, nearly doubles.
02 · Why shares mislead
The same data, two readings
A share is a composition. Severe PGD has more deaths to compose, so a cause can shrink as a fraction while growing as a rate. Infection is the clearest case: 20.5% of severe-PGD first-year deaths against 26.3% of no-PGD deaths — yet 42.1 against 23.2 per 1,000 recipients.
Share of that grade's first-year deaths (%)
no PGDmoderatesevere
First-year deaths per 1,000 recipients at risk
Denominators. The rate panel divides by recipients at risk — 6,003 with no PGD, 3,314 moderate, 4,539 severe — not by deaths. Every bar in the lower chart is comparable across grades; the bars in the upper one are only comparable within a grade.
03 · Specific causes
What the first year actually looks like in severe PGD
The most frequent recorded causes among the 932 severe-PGD recipients who died within a year.
Recorded cause
Deaths
Share
Multiple Organ Failure
158
17.0%
Infection: Bacterial Septicemia
85
9.1%
Pulm: Respiratory Failure
81
8.7%
Other Specify
76
8.2%
Graft Failure: Primary Failure
72
7.7%
Cardiovascular: Cardiac Arrest
44
4.7%
These are consequences, not competing explanations. Multi-organ failure, septicemia and respiratory failure are the pathways by which a severely dysfunctional graft kills in the first months — prolonged ventilation and extracorporeal support, then infection, then systemic failure. They are what the 24.7-per-1,000 graft-failure rate looks like clinically once it stops being a gas-exchange number.