Professor Stephen Westaby is, according to his own description, “an ambitious bastard” who suffers from an irritable bladder. He is also a maverick and a hugely innovative pioneer, internationally renowned as a heart surgeon who has helped to develop and refine the use of heart pumps, artificial hearts and circulatory support technology to drive blood around the body.

He wants these deployed not just as a temporary measure prior to a transplant, but to give an ailing heart time to recover or to provide an alternative to death when a patient is “walking dead” – refused a place on the transplant waiting list, chronically short of breath, bloated by retained fluid and fearful of what could happen next. Transplants – 200 a year in the UK – are funded by the NHS, but less so this “bridge to life” approach. As a result, Westaby argues, 12,000 people a year die unnecessarily. He is angry about “the rise and fall of the NHS”.

In his powerful book, Fragile Lives: A Heart Surgeon’s Stories of Life and Death on the Operating Table, Westaby tells how “the back-street boy” from a Scunthorpe council estate decided to become a heart surgeon at the age of seven, prompted by watching American surgeons performing a hole-in-the-heart operation on television. His grandad, a steelworker, was felled at 63 by heart disease. His grandmother died of thyroid cancer soon after. The awful manner of their deaths has been a lifelong spur.

Westaby has always taken the apparently hopeless adult cases and the complex congenital anomalies in the very young, with hearts swollen by disease from the proportions of a walnut to a lemon. Failure brings “shit and derision”. He has a buccaneer style, an Errol Flynn in scrubs. “The grim reaper was visiting this battle,” he writes. “And about to swing his scythe.”

The heart is wondrous in its design. It beats more than 60 times per minute, 31m times a year, “contraction and relaxation… narrowing, twisting and shortening… a veritable Argentine tango”.

As a rugby-playing, testosterone-fuelled medical student, aged 18, he illicitly watched from the eaves of the Ether Dome, in the then Charing Cross hospital, as a 26-year-old woman called Beth was operated on for a heart weakened by rheumatic fever. She died. A year later, Christiaan Barnard performed the first human-to-human heart transplant. The patient lived for 18 days.

“Beth wanted me to be a cardiac surgeon,” Westaby writes, complex surgery out of his reach today because of a distorted hand caused by Dupuytren’s contracture. “And I didn’t disappoint her. I was good at it.”

Westaby’s mantra is: “Move on, learn, try harder.” Innovation, he argues, is the goal, not outcomes. Since 2013, performance has been measured in “surgeon-specific mortality data”. As a result, he believes that cardiac surgery is too risky today for young students. They are “downtrodden, defensive, uncertain of themselves”.

In the 60s, a heart attack meant seven out of 10 patients died. Now, seven out of 10 survive, but one person with cardiovascular disease dies every three minutes. Questions arise as Westaby chronicles his life. Is he motivated by an opportunity to write an academic paper? Attract publicity? Push research and treatment a little further? Save a patient when the alternative is death? And, for the reader, which takes priority and what weight does quality of life have against the drive to intervene medically, often repeatedly and brutally, because professionals can?

Similar questions arise in Emergency Admissions: Memoirs of an Ambulance Driver by Kit Wharton, which documents the people he has helped and ferried since joining the ambulance service in 2003. Wharton’s father was treated in the John Radcliffe hospital, Oxford, Westaby’s domain, after a massive stroke in 1995 and kept alive in a vegetative state for 18 months. “Would it have been better to let him go?” Wharton asks. “What do I know?” But we do know. We, the public, want the medical profession to break the rules, except when we don’t – and therein lies a huge ethical dilemma.

Wharton describes with black humour how he was reared in a dysfunctional family – “EastEnders with posh people”. His father, “a serious journalist”, lived apart with his wife and children, visiting Wharton’s mother and the two children she’d had with him – his “second-class family” – for frequently drunken battles. Wharton (a former journalist himself) is passionate about his job. He delivers to hospital the “frequent flyers… that have scratched their fingers opening their dole cheque. And those broken by life.”

Westaby and the NHS were born in the same month in the same year, July 1948, when demand was for acute care. People on average did not have long lives. Now an ageing population, medical breakthroughs, not least the kind in which Westaby has specialised all his professional life, and conditions that are the product, paradoxically, of affluence and deprivation – obesity, cancer, asthma – mean millions live many years with costly chronic disease.

Now who gets what, when and on what criteria prompts Westaby’s profound frustration at “the Stasi”. Providing an artificial heart costs hundreds of thousands of pounds. The longest a recipient has lived, Peter Houghton, operated on by Westaby in 2000, is seven years. Houghton carried the batteries for his heart in a shoulder bag and had a plug in his head. When questioned about his extra lease of life, Houghton replied: “Three days out of five, it’s better than being dead.”

Fragile Lives is not for the faint-hearted; breast bones are sawn apart, body fluids gush, but empathy isn’t absent. In 1998, Julie, a 20-year-old student, is healthy one week and has a heart dangerously weakened by a viral infection the next. Westaby operates – “[I] ran the saw up the sternum” – and inserts a new American pump, an AB-180. He has no permission from the hospital ethics committee and no idea how the bills will be paid. “I was not the kind of doctor who’d let a young patient die because of some bureaucratic detail.”

Julie is alive today, as is Kirsty, operated on as a six-month-old baby, with Westaby innovating as he cuts, and learning in both cases that, given a chance, the heart can heal itself: a groundbreaking discovery.

Westaby spent years in a draughty portable building at the John Radcliffe hospital fighting for funds. Now he is in the private sector, based at Swansea University, continuing to develop heart technology and the use of stem cells. Wharton works on in an NHS that is weak at the knees, reeling from serial reorganisations, underfunding, managerial overload and privatisation, applying sticking plasters to diseases spawned by inequality.

Chroniclers such as Westaby and Wharton are much needed to remind us of the ethical dilemmas that have yet to be resolved, the value of vocation and why, for all its flaws, the NHS is a public service that must not be allowed to die.

• Fragile Lives: A Heart Surgeon’s Stories of Life and Death on the Operating Table by Stephen Westaby is published by Harper Collins (£12.99). Emergency Admissions by Kit Wharton is published by 4th Estate (£9.99). To order copies for £11.04 and £7.49 respectively, go to bookshop.theguardian.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min p&p of £1.99