Table II.

A summary of case reports according to documented blood cobalt level. The normal recorded values for left ventricular ejection fraction were 55% to 70%.

Blood cobalt levels (µg/l)	Patients, n	Mean blood cobalt levels, µg/l (range)	Cardiac presentation	Implants	Echocardiography results	Outcome	References
> 250	11	1,049 (258 to 6521)	Cardiogenic shock (1 case), cardiomyopathy (2 cases), dyspnoea (5 cases), fatigue (4 cases), exertional dyspnoea and cough (1 case),	CoC revised to MoP (7 cases), CoP revised to MoP (1 case), primary MoM resurfacing (1 case), bilateral primary MoM resurfacings (1 case)	Decreased LVEF (5 cases), mean LVEF reported was 17% (range 10% to 25%), pericardial effusion (2 cases), LVH (3 cases)	Death (27%, 3 cases), chelation and revision resolved symptoms (27%), revision resolved symptoms (27%), heart transplantation (18%, 2 cases)	43,44,52-56,59-61
200 to 300	2	Unknown	Dyspnoea, heart failure	Primary bilateral MoM resurfacing, primary MoM resurfacing	Decreased LVEF, mean LVEF 13%	Death (100%, both cases)	46,51
< 250	10	119.5 (13 to 246)	Heart failure (2 cases), dyspnoea (5 cases), exertional chest pain (3 cases), orthopnoea (1 case)	Bilateral primary MoM arthroplasties (3 cases), primary MoM arthroplasties (4 cases), CoC revised to MoP (2 cases), revision MoM arthroplasty (1 case)	Decreased LVEF (7 cases), mean LVEF reported was 24% (range 10% to 36%), diastolic dysfunction (2 cases), dilated cardiomyopathy (2 cases), pericardial effusion (1 case)	Heart transplantation and revision (30% 3 cases), revision resolved symptoms (60% 6 cases), LVAD and revision (10%, 1 case)	39-41,45,47-50,53,58

CoC, ceramic-on-ceramic; LVAD, left ventricular assist device; LVEF, left ventricular ejection fraction; MoM, metal-on-metal; MoP, metal-on-polyethylene.